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  • Excessive CPU Utilization for Bind 9.8.1 `named` processes

    - by justinzane
    I just noticed that named is eating vast amounts of CPU time for a very small network with only a few domains. Can someone help me determine what is misconfigured, please? Or how to debug this. top top - 14:13:08 up 25 days, 14:16, 1 user, load average: 1.04, 1.04, 1.05 Tasks: 149 total, 1 running, 148 sleeping, 0 stopped, 0 zombie %Cpu(s): 17.3 us, 4.3 sy, 0.0 ni, 78.2 id, 0.1 wa, 0.0 hi, 0.0 si, 0.0 st KiB Mem: 2042776 total, 1347916 used, 694860 free, 249396 buffers KiB Swap: 3976080 total, 30552 used, 3945528 free, 574164 cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 17445 bind 20 0 244m 42m 3124 S 99.4 2.2 2345:03 named rndc stats +++ Statistics Dump +++ (1352931389) ++ Incoming Requests ++ 65869 QUERY ++ Incoming Queries ++ 31809 A 241 NS 3 CNAME 27455 SOA 276 PTR 123 MX 462 TXT 5400 AAAA 7 A6 1 DS 14 DNSKEY 15 SPF 55 AXFR 8 ANY ++ Outgoing Queries ++ [View: internal] 22206 A 509 NS 10 SOA 25 PTR 12 MX 524 TXT 4851 AAAA 62 DNSKEY 19 SPF 3157 DLV [View: external] 87 A 2 NS 80 AAAA 120 DNSKEY 7 DLV [View: _bind] ++ Name Server Statistics ++ 65869 IPv4 requests received 27670 requests with EDNS(0) received 112 TCP requests received 65652 responses sent 20 truncated responses sent 27670 responses with EDNS(0) sent 62920 queries resulted in successful answer 37117 queries resulted in authoritative answer 28482 queries resulted in non authoritative answer 7 queries resulted in referral answer 591 queries resulted in nxrrset 53 queries resulted in SERVFAIL 2081 queries resulted in NXDOMAIN 14530 queries caused recursion 162 duplicate queries received 55 requested transfers completed ++ Zone Maintenance Statistics ++ 109536 IPv4 notifies sent ++ Resolver Statistics ++ [Common] [View: internal] 29362 IPv4 queries sent 2013 IPv6 queries sent 28531 IPv4 responses received 4209 NXDOMAIN received 6 SERVFAIL received 31 FORMERR received 32 EDNS(0) query failures 3359 query retries 836 query timeouts 5348 IPv4 NS address fetches 3271 IPv6 NS address fetches 83 IPv4 NS address fetch failed 2779 IPv6 NS address fetch failed 17421 DNSSEC validation attempted 12731 DNSSEC validation succeeded 4690 DNSSEC NX validation succeeded 21104 queries with RTT 10-100ms 7418 queries with RTT 100-500ms 3 queries with RTT 500-800ms 1 queries with RTT 800-1600ms [View: external] 192 IPv4 queries sent 104 IPv6 queries sent 192 IPv4 responses received 2 NXDOMAIN received 104 query retries 44 IPv4 NS address fetches 44 IPv6 NS address fetches 1 IPv4 NS address fetch failed 1 IPv6 NS address fetch failed 4 DNSSEC validation attempted 3 DNSSEC validation succeeded 1 DNSSEC NX validation succeeded 152 queries with RTT 10-100ms 40 queries with RTT 100-500ms [View: _bind] ++ Cache DB RRsets ++ [View: internal (Cache: internal)] 2007 A 652 NS 131 CNAME 1 MX 32 TXT 421 AAAA 28 DS 244 RRSIG 110 NSEC 3 DNSKEY 2 !A 2 !TXT 89 !AAAA 2 !SPF 14 !DLV 148 NXDOMAIN [View: external (Cache: external)] 55 A 12 NS 34 AAAA 2 DS 10 RRSIG 1 DNSKEY [View: _bind (Cache: _bind)] ++ Socket I/O Statistics ++ 82958 UDP/IPv4 sockets opened 2118 UDP/IPv6 sockets opened 4 TCP/IPv4 sockets opened 1 TCP/IPv6 sockets opened 82956 UDP/IPv4 sockets closed 2117 UDP/IPv6 sockets closed 58 TCP/IPv4 sockets closed 15 UDP/IPv4 socket bind failures 2117 UDP/IPv6 socket connect failures 29554 UDP/IPv4 connections established 59 TCP/IPv4 connections accepted 2117 UDP/IPv6 send errors 5 UDP/IPv4 recv errors ++ Per Zone Query Statistics ++ --- Statistics Dump --- (1352931389)

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  • POST Fail via AJAX Request?

    - by Jascha
    I can't for the life of me figure out why this is happening. This is kind of a repost (submitted to stackoverflow, but maybe a server issue?). I am running a javascript log out function called logOut() that has make a jQuery ajax call to a php script... function logOut(){ var data = new Object; data.log_out = true; $.ajax({ type: 'POST', url: 'http://www.mydomain.com/functions.php', data: data, success: function() { alert('done'); } }); } the php function it calls is here: if(isset($_POST['log_out'])){ $query = "INSERT INTO `token_manager` (`ip_address`) VALUES('logOutSuccess')"; $connection->runQuery($query); // <-- my own database class... // omitted code that clears session etc... die(); } Now, 18 hours out of the day this works, but for some reason, every once in a while, the POST data will not trigger my query. (this will last about an hour or so). I figured out the post data is not being set by adding this at the end of my script... $query = "INSERT INTO `token_manager` (`ip_address`) VALUES('POST FAIL')"; $connection->runQuery($query); So, now I know for certain my log out function is being skipped because in my database is the following data: if it were NOT being skipped, my data would show up like this: I know it is being skipped for two reasons, one the die() at the end of my first function, and two, if it were a success a "logOutSuccess" would be registered in the table. Any thoughts? One friend says it's a janky hosting company (hostgator.com). I personally like them because they are cheap and I'm a fan of cpanel. But, if that's the case??? Thanks in advance. -J

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  • quick look at: dm_db_index_physical_stats

    - by fatherjack
    A quick look at the key data from this dmv that can help a DBA keep databases performing well and systems online as the users need them. When the dynamic management views relating to index statistics became available in SQL Server 2005 there was much hype about how they can help a DBA keep their servers running in better health than ever before. This particular view gives an insight into the physical health of the indexes present in a database. Whether they are use or unused, complete or missing some columns is irrelevant, this is simply the physical stats of all indexes; disabled indexes are ignored however. In it’s simplest form this dmv can be executed as:   The results from executing this contain a record for every index in every database but some of the columns will be NULL. The first parameter is there so that you can specify which database you want to gather index details on, rather than scan every database. Simply specifying DB_ID() in place of the first NULL achieves this. In order to avoid the NULLS, or more accurately, in order to choose when to have the NULLS you need to specify a value for the last parameter. It takes one of 4 values – DEFAULT, ‘SAMPLED’, ‘LIMITED’ or ‘DETAILED’. If you execute the dmv with each of these values you can see some interesting details in the times taken to complete each step. DECLARE @Start DATETIME DECLARE @First DATETIME DECLARE @Second DATETIME DECLARE @Third DATETIME DECLARE @Finish DATETIME SET @Start = GETDATE() SELECT * FROM [sys].[dm_db_index_physical_stats](DB_ID(), NULL, NULL, NULL, DEFAULT) AS ddips SET @First = GETDATE() SELECT * FROM [sys].[dm_db_index_physical_stats](DB_ID(), NULL, NULL, NULL, 'SAMPLED') AS ddips SET @Second = GETDATE() SELECT * FROM [sys].[dm_db_index_physical_stats](DB_ID(), NULL, NULL, NULL, 'LIMITED') AS ddips SET @Third = GETDATE() SELECT * FROM [sys].[dm_db_index_physical_stats](DB_ID(), NULL, NULL, NULL, 'DETAILED') AS ddips SET @Finish = GETDATE() SELECT DATEDIFF(ms, @Start, @First) AS [DEFAULT] , DATEDIFF(ms, @First, @Second) AS [SAMPLED] , DATEDIFF(ms, @Second, @Third) AS [LIMITED] , DATEDIFF(ms, @Third, @Finish) AS [DETAILED] Running this code will give you 4 result sets; DEFAULT will have 12 columns full of data and then NULLS in the remainder. SAMPLED will have 21 columns full of data. LIMITED will have 12 columns of data and the NULLS in the remainder. DETAILED will have 21 columns full of data. So, from this we can deduce that the DEFAULT value (the same one that is also applied when you query the view using a NULL parameter) is the same as using LIMITED. Viewing the final result set has some details that are worth noting: Running queries against this view takes significantly longer when using the SAMPLED and DETAILED values in the last parameter. The duration of the query is directly related to the size of the database you are working in so be careful running this on big databases unless you have tried it on a test server first. Let’s look at the data we get back with the DEFAULT value first of all and then progress to the extra information later. We know that the first parameter that we supply has to be a database id and for the purposes of this blog we will be providing that value with the DB_ID function. We could just as easily put a fixed value in there or a function such as DB_ID (‘AnyDatabaseName’). The first columns we get back are database_id and object_id. These are pretty explanatory and we can wrap those in some code to make things a little easier to read: SELECT DB_NAME([ddips].[database_id]) AS [DatabaseName] , OBJECT_NAME([ddips].[object_id]) AS [TableName] … FROM [sys].[dm_db_index_physical_stats](DB_ID(), NULL, NULL, NULL, NULL) AS ddips  gives us   SELECT DB_NAME([ddips].[database_id]) AS [DatabaseName] , OBJECT_NAME([ddips].[object_id]) AS [TableName], [i].[name] AS [IndexName] , ….. FROM [sys].[dm_db_index_physical_stats](DB_ID(), NULL, NULL, NULL, NULL) AS ddips INNER JOIN [sys].[indexes] AS i ON [ddips].[index_id] = [i].[index_id] AND [ddips].[object_id] = [i].[object_id]     These handily tie in with the next parameters in the query on the dmv. If you specify an object_id and an index_id in these then you get results limited to either the table or the specific index. Once again we can place a  function in here to make it easier to work with a specific table. eg. SELECT * FROM [sys].[dm_db_index_physical_stats] (DB_ID(), OBJECT_ID(‘AdventureWorks2008.Person.Address’) , 1, NULL, NULL) AS ddips   Note: Despite me showing that functions can be placed directly in the parameters for this dmv, best practice recommends that functions are not used directly in the function as it is possible that they will fail to return a valid object ID. To be certain of not passing invalid values to this function, and therefore setting an automated process off on the wrong path, declare variables for the OBJECT_IDs and once they have been validated, use them in the function: DECLARE @db_id SMALLINT; DECLARE @object_id INT; SET @db_id = DB_ID(N’AdventureWorks_2008′); SET @object_id = OBJECT_ID(N’AdventureWorks_2008.Person.Address’); IF @db_id IS NULL BEGINPRINT N’Invalid database’; ENDELSE IF @object_id IS NULL BEGINPRINT N’Invalid object’; ENDELSE BEGINSELECT * FROM sys.dm_db_index_physical_stats (@db_id, @object_id, NULL, NULL , ‘LIMITED’); END; GO In cases where the results of querying this dmv don’t have any effect on other processes (i.e. simply viewing the results in the SSMS results area)  then it will be noticed when the results are not consistent with the expected results and in the case of this blog this is the method I have used. So, now we can relate the values in these columns to something that we recognise in the database lets see what those other values in the dmv are all about. The next columns are: We’ll skip partition_number, index_type_desc, alloc_unit_type_desc, index_depth and index_level  as this is a quick look at the dmv and they are pretty self explanatory. The final columns revealed by querying this view in the DEFAULT mode are avg_fragmentation_in_percent. This is the amount that the index is logically fragmented. It will show NULL when the dmv is queried in SAMPLED mode. fragment_count. The number of pieces that the index is broken into. It will show NULL when the dmv is queried in SAMPLED mode. avg_fragment_size_in_pages. The average size, in pages, of a single fragment in the leaf level of the IN_ROW_DATA allocation unit. It will show NULL when the dmv is queried in SAMPLED mode. page_count. Total number of index or data pages in use. OK, so what does this give us? Well, there is an obvious correlation between fragment_count, page_count and avg_fragment_size-in_pages. We see that an index that takes up 27 pages and is in 3 fragments has an average fragment size of 9 pages (27/3=9). This means that for this index there are 3 separate places on the hard disk that SQL Server needs to locate and access to gather the data when it is requested by a DML query. If this index was bigger than 72KB then having it’s data in 3 pieces might not be too big an issue as each piece would have a significant piece of data to read and the speed of access would not be too poor. If the number of fragments increases then obviously the amount of data in each piece decreases and that means the amount of work for the disks to do in order to retrieve the data to satisfy the query increases and this would start to decrease performance. This information can be useful to keep in mind when considering the value in the avg_fragmentation_in_percent column. This is arrived at by an internal algorithm that gives a value to the logical fragmentation of the index taking into account the multiple files, type of allocation unit and the previously mentioned characteristics if index size (page_count) and fragment_count. Seeing an index with a high avg_fragmentation_in_percent value will be a call to action for a DBA that is investigating performance issues. It is possible that tables will have indexes that suffer from rapid increases in fragmentation as part of normal daily business and that regular defragmentation work will be needed to keep it in good order. In other cases indexes will rarely become fragmented and therefore not need rebuilding from one end of the year to another. Keeping this in mind DBAs need to use an ‘intelligent’ process that assesses key characteristics of an index and decides on the best, if any, defragmentation method to apply should be used. There is a simple example of this in the sample code found in the Books OnLine content for this dmv, in example D. There are also a couple of very popular solutions created by SQL Server MVPs Michelle Ufford and Ola Hallengren which I would wholly recommend that you review for much further detail on how to care for your SQL Server indexes. Right, let’s get back on track then. Querying the dmv with the fifth parameter value as ‘DETAILED’ takes longer because it goes through the index and refreshes all data from every level of the index. As this blog is only a quick look a we are going to skate right past ghost_record_count and version_ghost_record_count and discuss avg_page_space_used_in_percent, record_count, min_record_size_in_bytes, max_record_size_in_bytes and avg_record_size_in_bytes. We can see from the details below that there is a correlation between the columns marked. Column 1 (Page_Count) is the number of 8KB pages used by the index, column 2 is how full each page is (how much of the 8KB has actual data written on it), column 3 is how many records are recorded in the index and column 4 is the average size of each record. This approximates to: ((Col1*8) * 1024*(Col2/100))/Col3 = Col4*. avg_page_space_used_in_percent is an important column to review as this indicates how much of the disk that has been given over to the storage of the index actually has data on it. This value is affected by the value given for the FILL_FACTOR parameter when creating an index. avg_record_size_in_bytes is important as you can use it to get an idea of how many records are in each page and therefore in each fragment, thus reinforcing how important it is to keep fragmentation under control. min_record_size_in_bytes and max_record_size_in_bytes are exactly as their names set them out to be. A detail of the smallest and largest records in the index. Purely offered as a guide to the DBA to better understand the storage practices taking place. So, keeping an eye on avg_fragmentation_in_percent will ensure that your indexes are helping data access processes take place as efficiently as possible. Where fragmentation recurs frequently then potentially the DBA should consider; the fill_factor of the index in order to leave space at the leaf level so that new records can be inserted without causing fragmentation so rapidly. the columns used in the index should be analysed to avoid new records needing to be inserted in the middle of the index but rather always be added to the end. * – it’s approximate as there are many factors associated with things like the type of data and other database settings that affect this slightly.  Another great resource for working with SQL Server DMVs is Performance Tuning with SQL Server Dynamic Management Views by Louis Davidson and Tim Ford – a free ebook or paperback from Simple Talk. Disclaimer – Jonathan is a Friend of Red Gate and as such, whenever they are discussed, will have a generally positive disposition towards Red Gate tools. Other tools are often available and you should always try others before you come back and buy the Red Gate ones. All code in this blog is provided “as is” and no guarantee, warranty or accuracy is applicable or inferred, run the code on a test server and be sure to understand it before you run it on a server that means a lot to you or your manager.

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  • Oracle SQL Developer: Fetching SQL Statement Result Sets

    - by thatjeffsmith
    Running queries, browsing tables – you are often faced with many thousands, if not millions, of rows. Most people are happy with looking at the first few rows. But occasionally you need to see more. SQL Developer doesn’t show you all records, all at once. Instead, it brings the records down in ‘chunks,’ or as-needed. How It Works There is a preference that tells SQL Developer how many records to get in a single request, or ‘fetch’ of records. The default is 50… So if I run a query that returns MORE than 50 rows: There’s more than 50 records in this resultset, but we have 50 in the grid to start with. We don’t know how many records are in this result set actually. To show the record count here, we actually go physically query the database with a row count type query. All we know is that the query has finished executing, and that there are rows available to go fetch. It tells us when it’s done. As you scroll through the grid, if you get to record 50 and scroll more, we’ll get 50 more records. Or, you can cheat to get to the ‘bottom’ of the result set. You can ask SQL Developer to just to get all the records at once… Once all the records have been fetched, you’ll see this: All rows fetched! A word of caution There’s a reason we have the default set to 50 and not 1000. Bringing back data can get expensive and heavy. We’ve found the best performance to be found in that 50 to 200 record range.

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  • MySQL Privileges required to GRANT EVENT, EXECUTE, LOCK TABLES, and TRIGGER

    - by Brad
    I have an account, user_a, and I would like to grant all available permissions on some_db to user_b. I have tried the following query: GRANT ALTER, ALTER ROUTINE, CREATE, CREATE ROUTINE, CREATE TEMPORARY TABLES, CREATE VIEW, DELETE, DROP, EVENT, EXECUTE, INDEX, INSERT, LOCK TABLES, REFERENCES, SELECT, SHOW VIEW, TRIGGER, UPDATE ON `some_db`.* TO 'user_b'@'%' WITH GRANT OPTION The result: Access denied for user 'user_a'@'%' to database 'some_db' Some experimentation has shown me that the only permissions my account (user_a) is unable to grant are EVENT, EXECUTE, LOCK TABLES, and TRIGGER. What privileges are required for my account to GRANT these privileges to another user? If I run SHOW GRANTS, I get this output: "GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, REFERENCES, INDEX, ALTER, SHOW DATABASES, SUPER, CREATE TEMPORARY TABLES, REPLICATION SLAVE, REPLICATION CLIENT, CREATE VIEW, SHOW VIEW, CREATE ROUTINE, ALTER ROUTINE, CREATE USER ON *.* TO 'user_a'@'%' IDENTIFIED BY PASSWORD '1234567890abcdef' WITH GRANT OPTION" "GRANT SELECT, INSERT, UPDATE, DELETE, EXECUTE ON `some_other_unrelated_db`.* TO 'user_a'@'%'" "GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, REFERENCES, INDEX, ALTER, CREATE TEMPORARY TABLES, LOCK TABLES, EXECUTE, CREATE ROUTINE, ALTER ROUTINE ON `another_unrelated_db`.* TO 'user_a'@'%' WITH GRANT OPTION"

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  • DB2 users and groups

    - by Arun Srini
    Just want to know everyone's experience and take on managing users/authentication on a multi-node db2 cluster with users groups. I have 17 apps in production (project based company, only 2 online apps), and some 30 users with 7 groups. prodsel - group that has select privilege on all tables produpdt - update group on selective tables (as required by the apps) proddel - delete prodins - insert permissions for the group Now what my company does is when an app uses certain user (called app1user), and needs select and insert privilege on a table, they 1. grant select and insert for prodsel, prodins respectively 2. add the user under those two groups... now this creates one to many relationship between user and privileges, and this app1user also gets select on other tables granted for the prodsel group. I know this is wrong. Before I explain, I need to know how this is done elsewhere. Please share your experiences, even if you use other Databases that uses OS level authentication.

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  • C#/.NET Little Wonders: Use Cast() and TypeOf() to Change Sequence Type

    - by James Michael Hare
    Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. We’ve seen how the Select() extension method lets you project a sequence from one type to a new type which is handy for getting just parts of items, or building new items.  But what happens when the items in the sequence are already the type you want, but the sequence itself is typed to an interface or super-type instead of the sub-type you need? For example, you may have a sequence of Rectangle stored in an IEnumerable<Shape> and want to consider it an IEnumerable<Rectangle> sequence instead.  Today we’ll look at two handy extension methods, Cast<TResult>() and OfType<TResult>() which help you with this task. Cast<TResult>() – Attempt to cast all items to type TResult So, the first thing we can do would be to attempt to create a sequence of TResult from every item in the source sequence.  Typically we’d do this if we had an IEnumerable<T> where we knew that every item was actually a TResult where TResult inherits/implements T. For example, assume the typical Shape example classes: 1: // abstract base class 2: public abstract class Shape { } 3:  4: // a basic rectangle 5: public class Rectangle : Shape 6: { 7: public int Widtgh { get; set; } 8: public int Height { get; set; } 9: } And let’s assume we have a sequence of Shape where every Shape is a Rectangle… 1: var shapes = new List<Shape> 2: { 3: new Rectangle { Width = 3, Height = 5 }, 4: new Rectangle { Width = 10, Height = 13 }, 5: // ... 6: }; To get the sequence of Shape as a sequence of Rectangle, of course, we could use a Select() clause, such as: 1: // select each Shape, cast it to Rectangle 2: var rectangles = shapes 3: .Select(s => (Rectangle)s) 4: .ToList(); But that’s a bit verbose, and fortunately there is already a facility built in and ready to use in the form of the Cast<TResult>() extension method: 1: // cast each item to Rectangle and store in a List<Rectangle> 2: var rectangles = shapes 3: .Cast<Rectangle>() 4: .ToList(); However, we should note that if anything in the list cannot be cast to a Rectangle, you will get an InvalidCastException thrown at runtime.  Thus, if our Shape sequence had a Circle in it, the call to Cast<Rectangle>() would have failed.  As such, you should only do this when you are reasonably sure of what the sequence actually contains (or are willing to handle an exception if you’re wrong). Another handy use of Cast<TResult>() is using it to convert an IEnumerable to an IEnumerable<T>.  If you look at the signature, you’ll see that the Cast<TResult>() extension method actually extends the older, object-based IEnumerable interface instead of the newer, generic IEnumerable<T>.  This is your gateway method for being able to use LINQ on older, non-generic sequences.  For example, consider the following: 1: // the older, non-generic collections are sequence of object 2: var shapes = new ArrayList 3: { 4: new Rectangle { Width = 3, Height = 13 }, 5: new Rectangle { Width = 10, Height = 20 }, 6: // ... 7: }; Since this is an older, object based collection, we cannot use the LINQ extension methods on it directly.  For example, if I wanted to query the Shape sequence for only those Rectangles whose Width is > 5, I can’t do this: 1: // compiler error, Where() operates on IEnumerable<T>, not IEnumerable 2: var bigRectangles = shapes.Where(r => r.Width > 5); However, I can use Cast<Rectangle>() to treat my ArrayList as an IEnumerable<Rectangle> and then do the query! 1: // ah, that’s better! 2: var bigRectangles = shapes.Cast<Rectangle>().Where(r => r.Width > 5); Or, if you prefer, in LINQ query expression syntax: 1: var bigRectangles = from s in shapes.Cast<Rectangle>() 2: where s.Width > 5 3: select s; One quick warning: Cast<TResult>() only attempts to cast, it won’t perform a cast conversion.  That is, consider this: 1: var intList = new List<int> { 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89 }; 2:  3: // casting ints to longs, this should work, right? 4: var asLong = intList.Cast<long>().ToList(); Will the code above work?  No, you’ll get a InvalidCastException. Remember that Cast<TResult>() is an extension of IEnumerable, thus it is a sequence of object, which means that it will box every int as an object as it enumerates over it, and there is no cast conversion from object to long, and thus the cast fails.  In other words, a cast from int to long will succeed because there is a conversion from int to long.  But a cast from int to object to long will not, because you can only unbox an item by casting it to its exact type. For more information on why cast-converting boxed values doesn’t work, see this post on The Dangers of Casting Boxed Values (here). OfType<TResult>() – Filter sequence to only items of type TResult So, we’ve seen how we can use Cast<TResult>() to change the type of our sequence, when we expect all the items of the sequence to be of a specific type.  But what do we do when a sequence contains many different types, and we are only concerned with a subset of a given type? For example, what if a sequence of Shape contains Rectangle and Circle instances, and we just want to select all of the Rectangle instances?  Well, let’s say we had this sequence of Shape: 1: var shapes = new List<Shape> 2: { 3: new Rectangle { Width = 3, Height = 5 }, 4: new Rectangle { Width = 10, Height = 13 }, 5: new Circle { Radius = 10 }, 6: new Square { Side = 13 }, 7: // ... 8: }; Well, we could get the rectangles using Select(), like: 1: var onlyRectangles = shapes.Where(s => s is Rectangle).ToList(); But fortunately, an easier way has already been written for us in the form of the OfType<T>() extension method: 1: // returns only a sequence of the shapes that are Rectangles 2: var onlyRectangles = shapes.OfType<Rectangle>().ToList(); Now we have a sequence of only the Rectangles in the original sequence, we can also use this to chain other queries that depend on Rectangles, such as: 1: // select only Rectangles, then filter to only those more than 2: // 5 units wide... 3: var onlyBigRectangles = shapes.OfType<Rectangle>() 4: .Where(r => r.Width > 5) 5: .ToList(); The OfType<Rectangle>() will filter the sequence to only the items that are of type Rectangle (or a subclass of it), and that results in an IEnumerable<Rectangle>, we can then apply the other LINQ extension methods to query that list further. Just as Cast<TResult>() is an extension method on IEnumerable (and not IEnumerable<T>), the same is true for OfType<T>().  This means that you can use OfType<TResult>() on object-based collections as well. For example, given an ArrayList containing Shapes, as below: 1: // object-based collections are a sequence of object 2: var shapes = new ArrayList 3: { 4: new Rectangle { Width = 3, Height = 5 }, 5: new Rectangle { Width = 10, Height = 13 }, 6: new Circle { Radius = 10 }, 7: new Square { Side = 13 }, 8: // ... 9: }; We can use OfType<Rectangle> to filter the sequence to only Rectangle items (and subclasses), and then chain other LINQ expressions, since we will then be of type IEnumerable<Rectangle>: 1: // OfType() converts the sequence of object to a new sequence 2: // containing only Rectangle or sub-types of Rectangle. 3: var onlyBigRectangles = shapes.OfType<Rectangle>() 4: .Where(r => r.Width > 5) 5: .ToList(); Summary So now we’ve seen two different ways to get a sequence of a superclass or interface down to a more specific sequence of a subclass or implementation.  The Cast<TResult>() method casts every item in the source sequence to type TResult, and the OfType<TResult>() method selects only those items in the source sequence that are of type TResult. You can use these to downcast sequences, or adapt older types and sequences that only implement IEnumerable (such as DataTable, ArrayList, etc.). Technorati Tags: C#,CSharp,.NET,LINQ,Little Wonders,TypeOf,Cast,IEnumerable<T>

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  • Sync Google Contacts with QuickBooks

    - by dataintegration
    The RSSBus ADO.NET Providers offer an easy way to integrate with different data sources. In this article, we include a fully functional application that can be used to synchronize contacts between Google and QuickBooks. Like our QuickBooks ADO.NET Provider, the included application supports both the desktop versions of QuickBooks and QuickBooks Online Edition. Getting the Contacts Step 1: Google accounts include a number of contacts. To obtain a list of a user's Google Contacts, issue a query to the Contacts table. For example: SELECT * FROM Contacts. Step 2: QuickBooks stores contact information in multiple tables. Depending on your use case, you may want to synchronize your Google Contacts with QuickBooks Customers, Employees, Vendors, or a combination of the three. To get data from a specific table, issue a SELECT query to that table. For example: SELECT * FROM Customers Step 3: Retrieving all results from QuickBooks may take some time, depending on the size of your company file. To narrow your results, you may want to use a filter by including a WHERE clause in your query. For example: SELECT * FROM Customers WHERE (Name LIKE '%James%') AND IncludeJobs = 'FALSE' Synchronizing the Contacts Synchronizing the contacts is a simple process. Once the contacts from Google and the customers from QuickBooks are available, they can be compared and synchronized based on user preference. The sample application does this based on user input, but it is easy to create one that does the synchronization automatically. The INSERT, UPDATE, and DELETE statements available in both data providers makes it easy to create, update, or delete contacts in either data source as needed. Pre-Built Demo Application The executable for the demo application can be downloaded here. Note that this demo is built using BETA builds of the ADO.NET Provider for Google V2 and ADO.NET Provider for QuickBooks V3, and will expire in 2013. Source Code You can download the full source of the demo application here. You will need the Google ADO.NET Data Provider V2 and the QuickBooks ADO.NET Data Provider V3, which can be obtained here.

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  • possible UDP attack on BIND?

    - by Waleed Hamra
    hello everyone, i was surprised last month when my EC2 instance (ubuntu precise server), that is supposed to be under the free tier still, accumulated lots of traffic... today, while checking my current billing statement, i noticed i already have tons of traffic, while still in the middle of the month, and i'm fearing what my bill by the end of the month is going to be... i installed bandwidthd, and after few minutes, i noticed lots of UDP traffic to "108.162.233.15". this is apparently a cloudflare IP, and i don't have anything using cloudflare (as far as i know). so i ran "iftop" to see what ports are being used, and i saw the UDP traffic coming from port 80 to my port 53... why would a webserver query dns? so i stopped bind on my server, and ran it in foreground debugging mode, and saw the following query, being repeated continuously: 17-Nov-2012 12:30:58.216 client 108.162.233.15#80: UDP request 17-Nov-2012 12:30:58.216 client 108.162.233.15#80: request is not signed 17-Nov-2012 12:30:58.216 client 108.162.233.15#80: recursion available 17-Nov-2012 12:30:58.216 client 108.162.233.15#80: query 17-Nov-2012 12:30:58.216 client 108.162.233.15#80: query (cache) 'isc.org/ANY/IN' approved 17-Nov-2012 12:30:58.216 client 108.162.233.15#80: send 17-Nov-2012 12:30:58.216 client 108.162.233.15#80: sendto 17-Nov-2012 12:30:58.216 client 108.162.233.15#80: senddone 17-Nov-2012 12:30:58.217 client 108.162.233.15#80: next 17-Nov-2012 12:30:58.217 client 108.162.233.15#80: endrequest 17-Nov-2012 12:30:58.217 client @0x7fbee05126e0: udprecv 17-Nov-2012 12:30:58.343 client 108.162.233.15#80: UDP request 17-Nov-2012 12:30:58.343 client 108.162.233.15#80: request is not signed 17-Nov-2012 12:30:58.343 client 108.162.233.15#80: recursion available 17-Nov-2012 12:30:58.343 client 108.162.233.15#80: query 17-Nov-2012 12:30:58.343 client 108.162.233.15#80: query (cache) 'isc.org/ANY/IN' approved 17-Nov-2012 12:30:58.343 client 108.162.233.15#80: send 17-Nov-2012 12:30:58.344 client 108.162.233.15#80: sendto 17-Nov-2012 12:30:58.344 client 108.162.233.15#80: senddone 17-Nov-2012 12:30:58.344 client 108.162.233.15#80: next 17-Nov-2012 12:30:58.344 client 108.162.233.15#80: endrequest my question is... is this normal? should i be worried? or is this completely irrelevant to my data charges, and i should wait to see more data from bandwidthd? thank you in advance.

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  • DNSSEC - Ad Flag not activated

    - by Arancha
    Hi all, I have some doubts regarding DNSSEC. I have one server acting as an Authoritative Name Server and another one as a Cache/Resolver. I'm using Bind 9.7.1-P2 and these are my configuration files: Named.conf (Authoritative Server) // Opciones de configuracion del servidor include "/etc/rndc.key"; controls { inet 127.0.0.1 allow { localhost; } keys { rndc-key; }; }; options{ version "Peticion no permitida/Query not allowed"; hostname "Peticion no permitida/Query not allowed"; server-id "Peticion no permitida/Query not allowed"; directory "/etc/DNS_RIMA"; pid-file "named.pid"; notify yes; #files 65535; dnssec-enable yes; dnssec-validation yes; allow-transfer { 172.23.2.37; 172.23.3.39; }; transfer-format many-answers; transfers-per-ns 5; transfers-in 10; max-transfer-time-in 120; check-names master ignore; listen-on {172.23.2.57; 80.58.102.13; 80.58.102.103; 127.0.0.1; }; }; zone "test.dnssec" { type master; key-directory "keys"; file "db.test.dnssec.signed"; also-notify { 172.23.2.37 ; 172.23.3.39 ; }; allow-transfer { 172.23.2.37 ; 172.23.3.39 ; }; }; test.dnssec zone test.dnssec. 86400 IN SOA ns.test.dnssec. mxadmin.test.dnssec. ( 2010090902 ; serial 21600 ; refresh (6 hours) 3600 ; retry (1 hour) 1814400 ; expire (3 weeks) 172800 ; minimum (2 days) ) 86400 RRSIG SOA 5 2 86400 20101009062248 ( 20100909062248 40665 test.dnssec. eY99laB6PrtETaXLdCS+G8Uq1lIK7d5vxUB1 pAQ9npv/YbvX1pdWZKGojDgPGw8V65Q0zKQo YW1VuBzvwfSRKax+yrjJzvHQGfCZPJWARehK hgLxHOfXLVH7tyndvLD49ZKcWtrop+Tuy4n9 apWWfSJZxCOngwS7zUi0zCTKfPs= ) 86400 NS ns1.test.dnssec. 86400 RRSIG NS 5 2 86400 20101009062248 ( 20100909062248 40665 test.dnssec. lmlP/Mb2qEXPSlajgSDn/CqWk/jokVCmqjeo idNuytxbiFnbCOunzvaYpgvDpEr0CPrwXaDL TSnb/w53tZl7GHRImJo50vwwNZljLzNT6CFw aaQXFc3rDLsXjCi+WF0/Z7meteM4jYdx5nrV Qx9pgur7VPbP88bJOqWCPBev2Ho= ) 172800 NSEC a.test.dnssec. NS SOA RRSIG NSEC DNSKEY 172800 RRSIG NSEC 5 2 172800 20101009062248 ( 20100909062248 40665 test.dnssec. E76ayamsAAz8Zcj7060KY0nTFzHPztM/Pkc5 OM0EcP7C5+ocn4L8M2J0rmR3jxfYvCpOk0BQ Zniqn9Aw41Qk068yJ2dfDPwV5zT0+te0nzwC /awJGPMXLzMj4JejYTlTiKfspGDJCG44F+lb lHXdcUhbjXf3loqMQadZFQ/eSn0= ) 86400 DNSKEY 256 3 5 ( AwEAAbQ8qrNN5vetx/7E1VOgXZ7fLqwG1y/i 55hWGCeLbcS95ratT9A6UospOvPSwPTlrFgF RWP67Pubzbsy7/damS1F1+p4GgBQway52Hd1 8HjdHKKC6kIxna9pOJBRfhCdzAsv9LnpRvrw mDpcFAqhdn5k5RqwcUF1eOZrKjxXjAOr ) ; key id = 40665 86400 DNSKEY 257 3 5 ( AwEAAcd4dxWyTgOuqha0DJADUH0pk5jvnwdM ZhgZaqnayUdeTh8U9WOjOUHdVCGywZS6NTVp xXqhcegWzh2ZR5VN6thuhezt7kbzLNWbPe7m YF29/ZTXB6nmdSxruQlSvYhzkWTaPNtfrUnI UlbDRxUFWQkSHj9LA1TG76FpR6uqOj1sNrWX nPb/Hwp1Sb2Ik4FlifKb/Vu1+/UnclRJgfPm p2HGTeNYpfk15JHBPSYxJ1TuedXQIdkPGlQX ISmAeV1evGomCC/x9DNleDHCszJOptwurzRP Z7wRXcWnbXz1BU8rAqvUZL3M4UgdNRR5LLTz CkRnrlvXYJpgzDtgmQxE9Bs= ) ; key id = 59647 86400 RRSIG DNSKEY 5 2 86400 20101009062248 ( 20100909062248 40665 test.dnssec. sa4W3tvl6n0TkIcq3xzhG17C2O0lRhllrpUd n5Hs6yVo8r7stewP6tm2XscQiAeseDgmv28w s6Mtiz8uPUbrgFRb6SJk7coH2n/2Y3//S9YP NldDFv3luPnnU1TBb3jDsBKIZWHU9yl/cLNA OKUhlMDd40txk+fQi3iiV5Ls9K8= ) 86400 RRSIG DNSKEY 5 2 86400 20101009062248 ( 20100909062248 59647 test.dnssec. b5fz0dEp2co2pVO7biY896XmsJanjQIR69vC MvSF104/9iZk6eGVFi6hsa4aZcXutEjUDESB ynPkDjMWWIIhN6K1jYKGIc/sFKv1IUONRYHF KXGgZhC6aI0B1E4NA9AXLjlBVF60nHdc3iw8 5gTLDjypP3qAZrnzMvdiBopLnVdB25UZYKn8 mGpOuzKqX02TGMCFMlEVtMX4FP/XKAE8UjiQ 5ehC1JvIKIyg/2zM+ot3nmcqqtUfzp/Hweyc aIkl/9wPJPwMedfTqOjfUKFdB+GiZ0Zz16HZ 5MfJui5IGh5Y6Q04kMrnap2V5U7mByTzx/ud V/eFYhmSHGtAXzBjMA== ) a.test.dnssec. 86400 IN A 1.1.1.1 86400 RRSIG A 5 3 86400 20101009062248 ( 20100909062248 40665 test.dnssec. P52N9ypCrYsgS4CFcUmII0xjyE6KNL9ndhzH oU63fHJHQHeQV+fc0Rx8cCmZSzuqk1lSBelV 3Gcl9UNNuCAQ4ORQ/yJkiZ1zn7h93Mep9qsg YEUQJMfk4FLjYW67DHNcuoCnKbDJhZS0ndVf I474k7ZEZJsGslwk/vcIoFnTa4o= ) 172800 NSEC b.test.dnssec. A RRSIG NSEC 172800 RRSIG NSEC 5 3 172800 20101009062248 ( 20100909062248 40665 test.dnssec. TCduf7xPSrWvEAzBO7Kx5haR85yA/lbsswkQ v0QxlskqAqo+9YedGQV+wGblbCIOmkomrYcq u/rXQ5yoQ3SDXd/bw6EFdoQmH8UJOjMc7SdR xY93MjawPB6XXlJsSlbBFPWJwEpILVRhdBFX czdS5VCa1KmhAYZYQp1FY9rMelA= ) b.test.dnssec. 86400 IN A 2.2.2.2 86400 RRSIG A 5 3 86400 20101009062248 ( 20100909062248 40665 test.dnssec. f0M6Tcqe6B09ctaN3BGAit4u4cJE8x3Ik8sh gyMu0GN/lMv/Bo7PB6hgylLam3HXtF1pPAzX oYudXmhU8afPapHMXfUitC1lFQB5ZW052ZC7 JXV9MnGULydz1blj2EdN+JL3Za8SJKM0LrLB XdQ+QUV+A/6N7hUV6usz5YmdBeI= ) 172800 NSEC ns1.test.dnssec. A RRSIG NSEC 172800 RRSIG NSEC 5 3 172800 20101009062248 ( 20100909062248 40665 test.dnssec. sc6v19dcOFVa295/Xf1pKxBhbdpEErY8CTDQ fw2fjJf0Y3wL1Y1Mlr5zi5ShceQwgua+6YHE DWNbAPcXrJ0lLMU4DU5r0sAyBiBCgCavngGk i59W+nv11zuIpPMnlaMHpJVfJrQ+c4z7H9MH 77B0fMRFTUnvAXoq6ag8Q5POITI= ) ns1.test.dnssec. 86400 IN A 3.3.3.3 86400 RRSIG A 5 3 86400 20101009062248 ( 20100909062248 40665 test.dnssec. UQ3hR/++ta1GokxGz8Yh+GomMcA+xhd3z2Ke z0tdFiNfxvGbm85XyCtSqJIo2S/ZLVJUv/mG nGJbicTfJSziKzYZsD7dp0WJiUK3l7lQ/HpP 5FL8SbjlovVYYAG5woW4p3+os28mmCAJA8gP JTywbcREEhFB4cir2M/QVP+9h+Y= ) 172800 NSEC test.dnssec. A RRSIG NSEC 172800 RRSIG NSEC 5 3 172800 20101009062248 ( 20100909062248 40665 test.dnssec. i7F/ezGl/pGXCC6JyVDaxuwdZMAgv9QLxwzi PTgjCG8Sj6pTIxaQkSLwXsoB9gF77WWBANow R2SWdz0Zai2vWnv/NYoNm9ZfRJEQ9NuExeYp rvX/+lLOHvZXN6tUerIQbWAxO2GwdzHoejSn wReUNVr9MxzZUvuJ33Z7X/7s9VQ= ) Named.conf (Cache/Resolver) include "/etc/rndc.key"; controls { inet 127.0.0.1 allow { localhost; } keys { rndc-key; }; }; options{ version "Peticion no permitida/Query not allowed"; hostname "Peticion no permitida/Query not allowed"; server-id "Peticion no permitida/Query not allowed"; directory "/etc/DNS_RIMA"; pid-file "named.pid"; recursion yes; notify no; #DNSSEC dnssec-enable yes; dnssec-validation yes; listen-on {127.0.0.1; 172.23.2.87; 80.58.102.37; 80.58.102.115; }; #listen-on {127.0.0.1; 80.58.102.37; 80.58.102.115; }; allow-query { telefonica; }; allow-transfer { none; }; recursive-clients 40000; max-cache-size 838860800; rrset-order { order fixed;}; max-ncache-ttl 600; }; trusted-keys { "test.dnssec." 257 3 5 "AwEAAcd4dxWyTgOuqha0DJADUH0pk5jvnwdMZhgZaqnayUdeTh8U9WOjOUHdVCGywZS6NTVpxXqhcegWzh2ZR5VN6thuhezt7kbzLNWbPe7mYF29/ZT XB6nmdSxruQlSvYhzkWTaPNtfrUnIUlbDRxUFWQkSHj9LA1TG76FpR6uqOj1sNrWXnPb/Hwp1Sb2Ik4FlifKb/Vu1+/UnclRJgfPmp2HGTeNYpfk15JHBPSYxJ1TuedXQIdkPGlQXIS mAeV1evGomCC/x9DNleDHCszJOptwurzRPZ7wRXcWnbXz1BU8rAqvUZL3M4UgdNRR5LLTzCkRnrlvXYJpgzDtgmQxE9Bs="; }; I have configured a secure zone (test.dnssec) and I'm trying to perform some queries from the resolver to the Name server (172.23.2.57): /usr/local/bin/dig @172.23.2.57 a.test.dnssec +dnssec ; <<>> DiG 9.7.1-P2 <<>> @172.23.2.57 a.test.dnssec +dnssec ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 2654 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 2, ADDITIONAL: 3 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags: do; udp: 4096 ;; QUESTION SECTION: ;a.test.dnssec. IN A ;; ANSWER SECTION: a.test.dnssec. 86400 IN A 1.1.1.1 a.test.dnssec. 86400 IN RRSIG A 5 3 86400 20101009062248 20100909062248 40665 test.dnssec. P52N9ypCrYsgS4CFcUmII0xjyE6KNL9ndhzHoU63fHJHQHeQV+ fc0Rx8 cCmZSzuqk1lSBelV3Gcl9UNNuCAQ4ORQ/yJkiZ1zn7h93Mep9qsgYEUQ JMfk4FLjYW67DHNcuoCnKbDJhZS0ndVfI474k7ZEZJsGslwk/vcIoFnT a4o= ;; AUTHORITY SECTION: test.dnssec. 86400 IN NS ns1.test.dnssec. test.dnssec. 86400 IN RRSIG NS 5 2 86400 20101009062248 20100909062248 40665 test.dnssec. lmlP/Mb2qEXPSlajgSDn/CqWk/jokVCmqjeoidNuytxbiFnbCOunzvaY pgvDpEr0CPrwXaDLTSnb/w53tZl7GHRImJo50vwwNZljLzNT6CFwaaQX Fc3rDLsXjCi+WF0/Z7meteM4jYdx5nrVQx9pgur7VPbP88bJOqWCPBev 2Ho= ;; ADDITIONAL SECTION: ns1.test.dnssec. 86400 IN A 3.3.3.3 ns1.test.dnssec. 86400 IN RRSIG A 5 3 86400 20101009062248 20100909062248 40665 test.dnssec. UQ3hR/++ta1GokxGz8Yh+GomMcA+xhd3z2Kez0tdFiNfxvGbm85XyCtS qJIo2S/ZLVJUv/mGnGJbicTfJSziKzYZsD7dp0WJiUK3l7lQ/HpP5FL8 SbjlovVYYAG5woW4p3+os28mmCAJA8gPJTywbcREEhFB4cir2M/QVP+9 h+Y= ;; Query time: 1 msec ;; SERVER: 172.23.2.57#53(172.23.2.57) ;; WHEN: Thu Sep 9 09:47:14 2010 ;; MSG SIZE rcvd: 605 I obtain the right answer along with the RRSIG records, but the problem is that I'm not seeing the ad flag activated. Any idea about what is wrong????

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  • Weird DNS bug - external server resolves to internal IP

    - by emilecantin
    I have a server that is hosted by my university. I have root access, but no control over network setup, firewall, etc. This server's DNS resolves to an internal IP here on campus (10.x.x.x), and an external IP outside campus. I also have a few servers hosted at Amazon, and they mostly work well. However, one of them started to resolve the university server by its internal IP address. This causes problems, as 10.x.x.x on Amazon EC2 is someone else. I have connected to the Amazon server with SSH agent forwarding a few times in the past, to access a Git repository on the university server. Any idea what could cause this? EDIT: Here's my /etc/resolv.conf # Generated by dhcpcd for interface eth0 search ec2.internal nameserver 172.16.0.23 Here's the output of dig myserver.myuniversity.ca.: ; <<>> DiG 9.8.1-P1 <<>> myserver.myuniversity.ca. ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 34470 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;myserver.myuniversity.ca. IN A ;; ANSWER SECTION: myserver.myuniversity.ca. 537586 IN A 10.43.x.x ;; Query time: 2 msec ;; SERVER: 172.16.0.23#53(172.16.0.23) ;; WHEN: Wed Nov 28 16:07:21 2012 ;; MSG SIZE rcvd: 60 Here's the expected output (on another Amazon server): ; <<>> DiG 9.8.1-P1 <<>> myserver.myuniversity.ca. ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 8045 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;myserver.myuniversity.ca. IN A ;; ANSWER SECTION: myserver.myuniversity.ca. 601733 IN A x.x.239.1 ;; Query time: 1 msec ;; SERVER: 172.16.0.23#53(172.16.0.23) ;; WHEN: Wed Nov 28 16:09:36 2012 ;; MSG SIZE rcvd: 60

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  • Column order can matter

    - by Dave Ballantyne
    Ordinarily, column order of a SQL statement does not matter. Select a,b,c from table will produce the same execution plan as   Select c,b,a from table However, sometimes it can make a difference.   Consider this statement (maxdop is used to make a simpler plan and has no impact to the main point):   select SalesOrderID, CustomerID, OrderDate, ROW_NUMBER() over (Partition By CustomerId order by OrderDate asc) as RownAsc, ROW_NUMBER() over (Partition By CustomerId order by OrderDate Desc) as RownDesc from sales.SalesOrderHeader order by CustomerID,OrderDateoption(maxdop 1) If you look at the execution plan, you will see similar to this That is three sorts.  One for RownAsc,  one for RownDesc and the final one for the ‘Order by’ clause.  Sorting is an expensive operation and one that should be avoided if possible.  So with this in mind, it may come as some surprise that the optimizer does not re-order operations to group them together when the incoming data is in a similar (if not exactly the same) sorted sequence.  A simple change to swap the RownAsc and RownDesc columns to produce this statement : select SalesOrderID, CustomerID, OrderDate, ROW_NUMBER() over (Partition By CustomerId order by OrderDate Desc) as RownDesc , ROW_NUMBER() over (Partition By CustomerId order by OrderDate asc) as RownAsc from Sales.SalesOrderHeader order by CustomerID,OrderDateoption(maxdop 1) Will result a different and more efficient query plan with one less sort. The optimizer, although unable to automatically re-order operations, HAS taken advantage of the data ordering if it is as required.  This is well worth taking advantage of if you have different sorting requirements in one statement. Try grouping the functions that require the same order together and save yourself a few extra sorts.

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  • Nodes inside Cisco VPN. Incoming SSH requests allowed. But can't initiate an outbound SSH.

    - by Douglas Peter
    I've a gateway-to-gateway VPN setup between my Linksys RV042 router and a Cisco VPN. I am able to SSH into any of the machine inside the VPN from my network. But none of the machines inside the VPN can initiate an SSH into my network. It seems they've blocked even all ping requests to my network gateway. This is the requirement: I have scripts that SSH into the machines inside the VPN and run a long mysql query. The query generates an output to a file. The time that these queries take is variable. So I have a loop in my machine that periodically SSHes into the VPN machine and checks if the query has finished, and pulls the generated file using SCP. I need to simplify it thus: The script will run at the machine inside the VPN, and when the query completes, it will SSH into my machine and pushes the generated file. Thanks for any ideas.

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  • How to log error queries in mysql?

    - by Kaizoku
    I know that there is general_log that logs all queries, but I want to find out which query has an error, and get the error message. I have tried running an error query on purpose, but it logs as a normal query and doesn't report it with error. Any ideas?

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  • How to determine if you should use full or differential backup?

    - by Peter Larsson
    Or ask yourself, "How much of the database has changed since last backup?". Here is a simple script that will tell you how much (in percent) have changed in the database since last backup. -- Prepare staging table for all DBCC outputs DECLARE @Sample TABLE         (             Col1 VARCHAR(MAX) NOT NULL,             Col2 VARCHAR(MAX) NOT NULL,             Col3 VARCHAR(MAX) NOT NULL,             Col4 VARCHAR(MAX) NOT NULL,             Col5 VARCHAR(MAX)         )   -- Some intermediate variables for controlling loop DECLARE @FileNum BIGINT = 1,         @PageNum BIGINT = 6,         @SQL VARCHAR(100),         @Error INT,         @DatabaseName SYSNAME = 'Yoda'   -- Loop all files to the very end WHILE 1 = 1     BEGIN         BEGIN TRY             -- Build the SQL string to execute             SET     @SQL = 'DBCC PAGE(' + QUOTENAME(@DatabaseName) + ', ' + CAST(@FileNum AS VARCHAR(50)) + ', '                             + CAST(@PageNum AS VARCHAR(50)) + ', 3) WITH TABLERESULTS'               -- Insert the DBCC output in the staging table             INSERT  @Sample                     (                         Col1,                         Col2,                         Col3,                         Col4                     )             EXEC    (@SQL)               -- DCM pages exists at an interval             SET    @PageNum += 511232         END TRY           BEGIN CATCH             -- If error and first DCM page does not exist, all files are read             IF @PageNum = 6                 BREAK             ELSE                 -- If no more DCM, increase filenum and start over                 SELECT  @FileNum += 1,                         @PageNum = 6         END CATCH     END   -- Delete all records not related to diff information DELETE FROM    @Sample WHERE   Col1 NOT LIKE 'DIFF%'   -- Split the range UPDATE  @Sample SET     Col5 = PARSENAME(REPLACE(Col3, ' - ', '.'), 1),         Col3 = PARSENAME(REPLACE(Col3, ' - ', '.'), 2)   -- Remove last paranthesis UPDATE  @Sample SET     Col3 = RTRIM(REPLACE(Col3, ')', '')),         Col5 = RTRIM(REPLACE(Col5, ')', ''))   -- Remove initial information about filenum UPDATE  @Sample SET     Col3 = SUBSTRING(Col3, CHARINDEX(':', Col3) + 1, 8000),         Col5 = SUBSTRING(Col5, CHARINDEX(':', Col5) + 1, 8000)   -- Prepare data outtake ;WITH cteSource(Changed, [PageCount]) AS (     SELECT      Changed,                 SUM(COALESCE(ToPage, FromPage) - FromPage + 1) AS [PageCount]     FROM        (                     SELECT CAST(Col3 AS INT) AS FromPage,                             CAST(NULLIF(Col5, '') AS INT) AS ToPage,                             LTRIM(Col4) AS Changed                     FROM    @Sample                 ) AS d     GROUP BY    Changed     WITH ROLLUP ) -- Present the final result SELECT  COALESCE(Changed, 'TOTAL PAGES') AS Changed,         [PageCount],         100.E * [PageCount] / SUM(CASE WHEN Changed IS NULL THEN 0 ELSE [PageCount] END) OVER () AS Percentage FROM    cteSource

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  • How to disable the Social Reader Application in Facebook?

    - by Rekha
    Social Reader Application has made the process of sharing in Facebook easy but it looks like whatever we read is being displayed in our Facebook’s page. How to avoid this sharing? In the recent days, everyone’s Facebook Page is being flooded with various news from all the Social Reader Applications we have enabled. Even though this is a good idea to share the current news to everyone, it still seems to have taken away our privacy of what content we actually read. To avoid displaying the news on our Facebook page: 1. If you want the feeds to be displayed in your page but not to be shown to public or friends, just select from the options that are listed when you give permission for the Social Reader when you first read a feed. 2. Select Account Settings from the drop down menu on the top right corner of your FB page. Select Apps Tab which is available in the left side of the page. Here you can change the App Settings or completely delete the App. 3. You can also block Social Reader and other applications’ feeds that are read by your friends. In the right corner of the feed, click the drop-down icon and select “Hide all by ‘Application’” option. By selecting this, you would not be able to see any feeds from your friends too. 4. If you are intrigued by the feeds, you can just copy the title in your search engine and then read directly from their sites. This will not list the feed in your Facebook page.

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  • Assistance on setup to Connect an offsite server to the LAN via RRAS VPN - Server 2008 R2

    - by Paul D'Ambra
    I have an office LAN protected using a Zyxel Zywall USG 300. I've set up an L2TP/ipsec VPN on that which accepts connections using a shared secret and I've tested this from multiple clients. I have a server offsite and want to set up RRAS to use a persistent connection to the VPN so that it can carry out network jobs even with no one logged in (I'm using it for Micorosft DPM secondary backup). If I create a vpn as if I were setting up a users laptop it can dial in no problem but if I set up a demand dial interface in RRAS it errors. I enable RRAS ticking only demand dial interface (branch office routing) Select network interfaces, right click and choose new demand dial interface Name the VPN ToCompany Select connect using VPN And then L2TP as the vpn type enter the IP address (double-checked for typos!) select Route IP packets on this interface specify static route to remote network as 10.0.0.0/24 with metric of 1 add dial out credentials (again double checked for typos and confirmed with other vpn connections click finish now I right-click on the new interface and choose properties and then the security tab I change Data encryption to optional select only PAP for Authentication (both as per manufacturer of Zywall) click advanced settings against type of vpn and set shared secret then I select the new interface, right-click and choose connect this dials and then errors with either 720 or 811 as the error codes. However, if I create a VPN by going to Network & Sharing center and setting up as if I was creating a VPN from my laptop to the office (say) it dials successfully so I know the VPN settings are correct and the machine can connect to the VPN. Suggests very strongly the problem is how I'm setting up RRAS. Can anyone help?

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  • Comparing Dates in Oracle Business Rule Decision Tables

    - by James Taylor
    I have been working with decision tables for some time but have never had a scenario where I need to compare dates. The use case was to check if a persons membership had expired. I didn't think much of it till I started to develop it. The first trap I feel into was trying to create ranges and bucket sets. The other trap I fell into was not converting the date field to a complete date. This may seem obvious to most people but my Google searches came up with nothing so I thought I would create a quick post. I assume everyone knows how to create a decision table so I'm not going to go through those steps. The prerequisite for this post is to have a decision table with a payload that has a date field. This filed must have the date in the following format YYYY-MM-DDThh:mm:ss. Create a new condition in your decision table Right-click on the condition to edit it and select the expression builder In the expression builder, select the Functions tab. Expand the CurrentDate file and select date, and click Insert Into Expression button. In the Expression Builder you need to create an expression that will return true or false, add the operation <= after the CurrentDate.date In my scenario my date field is memberExpire, Navigate to your date field and expand, select toGregorianCalendar(). Your expression will look something like this, click OK to get back to the decision table Now its just a matter of checking if the value is true or false. Simple when you know how :-)

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  • n00b needs some PHP syntax guidance [closed]

    - by Michael
    If you look at http://www.cruc.es/?paged=12/ and go to the bottom of the page you'll see the bottom navigation with the next and previous options. I've been able to make the page numbers work by changing page to paged= in the code. I don't know enough about PHP to get the previous/next options to work. Any advice would be appreciated and I've pasted the code below. Thank you: n00b if ( $query->found_posts > $query->query_vars["posts_per_page"] ) { echo '<ul class="paging">'; // Previous link? if ( $page > 1 ) { echo '<li class="previous"><a href="'.$baseURL.'/page/'.($page-1).'/'.$qs.'">previous</a></li>'; } // Loop through pages for ( $i=1; $i <= $query->max_num_pages; $i++ ) { // Current page or linked page? if ( $i == $page ) { echo '<li class="active">'.$i.'</li>'; } else { echo '<li><a href="'.$baseURL.'/?paged='.$i.'/'.$qs.'">'.$i.'</a></li>'; } } // Next link? if ( $page < $query->max_num_pages ) { echo '<li><a href="'.$baseURL.'/page/'.($page+1).'/'.$qs.'">next</a></li>'; } echo '</ul>'; }

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  • Deleting a row from self-referencing table

    - by Jake Rutherford
    Came across this the other day and thought “this would be a great interview question!” I’d created a table with a self-referencing foreign key. The application was calling a stored procedure I’d created to delete a row which caused but of course…a foreign key exception. You may say “why not just use a the cascade delete option?” Good question, easy answer. With a typical foreign key relationship between different tables which would work. However, even SQL Server cannot do a cascade delete of a row on a table with self-referencing foreign key. So, what do you do?…… In my case I re-wrote the stored procedure to take advantage of recursion:   -- recursively deletes a Foo ALTER PROCEDURE [dbo].[usp_DeleteFoo]      @ID int     ,@Debug bit = 0    AS     SET NOCOUNT ON;     BEGIN TRANSACTION     BEGIN TRY         DECLARE @ChildFoos TABLE         (             ID int         )                 DECLARE @ChildFooID int                        INSERT INTO @ChildFoos         SELECT ID FROM Foo WHERE ParentFooID = @ID                 WHILE EXISTS (SELECT ID FROM @ChildFoos)         BEGIN             SELECT TOP 1                 @ChildFooID = ID             FROM                 @ChildFoos                             DELETE FROM @ChildFoos WHERE ID = @ChildFooID                         EXEC usp_DeleteFoo @ChildFooID         END                                    DELETE FROM dbo.[Foo]         WHERE [ID] = @ID                 IF @Debug = 1 PRINT 'DEBUG:usp_DeleteFoo, deleted - ID: ' + CONVERT(VARCHAR, @ID)         COMMIT TRANSACTION     END TRY     BEGIN CATCH         ROLLBACK TRANSACTION         DECLARE @ErrorMessage VARCHAR(4000), @ErrorSeverity INT, @ErrorState INT         SELECT @ErrorMessage = ERROR_MESSAGE(), @ErrorSeverity = ERROR_SEVERITY(), @ErrorState = ERROR_STATE()         IF @ErrorState <= 0 SET @ErrorState = 1         INSERT INTO ErrorLog(ErrorNumber,ErrorSeverity,ErrorState,ErrorProcedure,ErrorLine,ErrorMessage)         VALUES(ERROR_NUMBER(), @ErrorSeverity, @ErrorState, ERROR_PROCEDURE(), ERROR_LINE(), @ErrorMessage)         RAISERROR (@ErrorMessage, @ErrorSeverity, @ErrorState)     END CATCH   This procedure will first determine any rows which have the row we wish to delete as it’s parent. It then simply iterates each child row calling the procedure recursively in order to delete all ancestors before eventually deleting the row we wish to delete.

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  • How-to read data from selected tree node

    - by Frank Nimphius
    Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} By default, the SelectionListener property of an ADF bound tree points to the makeCurrent method of the FacesCtrlHierBinding class in ADF to synchronize the current row in the ADF binding layer with the selected tree node. To customize the selection behavior, or just to read the selected node value in Java, you override the default configuration with an EL string pointing to a managed bean method property. In the following I show how you change the selection listener while preserving the default ADF selection behavior. To change the SelectionListener, select the tree component in the Structure Window and open the Oracle JDeveloper Property Inspector. From the context menu, select the Edit option to create a new listener method in a new or an existing managed bean. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} For this example, I created a new managed bean. On tree node select, the managed bean code prints the selected tree node value(s) import java.util.List; import javax.el.ELContext; import javax.el.ExpressionFactory; import javax.el.MethodExpression; import javax.faces.application.Application; import javax.faces.context.FacesContext; import java.util.Iterator; import oracle.adf.view.rich.component.rich.data.RichTree; import oracle.jbo.Row; import oracle.jbo.uicli.binding.JUCtrlHierBinding; import oracle.jbo.uicli.binding.JUCtrlHierNodeBinding; import org.apache.myfaces.trinidad.event.SelectionEvent; import org.apache.myfaces.trinidad.model.CollectionModel; import org.apache.myfaces.trinidad.model.RowKeySet; import org.apache.myfaces.trinidad.model.TreeModel; public class TreeSampleBean { public TreeSampleBean() {} public void onTreeSelect(SelectionEvent selectionEvent) { //original selection listener set by ADF //#{bindings.allDepartments.treeModel.makeCurrent} String adfSelectionListener = "#{bindings.allDepartments.treeModel.makeCurrent}";   //make sure the default selection listener functionality is //preserved. you don't need to do this for multi select trees //as the ADF binding only supports single current row selection     /* START PRESERVER DEFAULT ADF SELECT BEHAVIOR */ FacesContext fctx = FacesContext.getCurrentInstance(); Application application = fctx.getApplication(); ELContext elCtx = fctx.getELContext(); ExpressionFactory exprFactory = application.getExpressionFactory();   MethodExpression me = null;   me = exprFactory.createMethodExpression(elCtx, adfSelectionListener,                                           Object.class, newClass[]{SelectionEvent.class});   me.invoke(elCtx, new Object[] { selectionEvent });     /* END PRESERVER DEFAULT ADF SELECT BEHAVIOR */   RichTree tree = (RichTree)selectionEvent.getSource(); TreeModel model = (TreeModel)tree.getValue();  //get selected nodes RowKeySet rowKeySet = selectionEvent.getAddedSet();   Iterator rksIterator = rowKeySet.iterator();   //for single select configurations,this only is called once   while (rksIterator.hasNext()) {     List key = (List)rksIterator.next();     JUCtrlHierBinding treeBinding = null;     CollectionModel collectionModel = (CollectionModel)tree.getValue();     treeBinding = (JUCtrlHierBinding)collectionModel.getWrappedData();     JUCtrlHierNodeBinding nodeBinding = null;     nodeBinding = treeBinding.findNodeByKeyPath(key);     Row rw = nodeBinding.getRow();     //print first row attribute. Note that in a tree you have to     //determine the node type if you want to select node attributes     //by name and not index      String rowType = rw.getStructureDef().getDefName();       if(rowType.equalsIgnoreCase("DepartmentsView")){      System.out.println("This row is a department: " +                          rw.getAttribute("DepartmentId"));     }     else if(rowType.equalsIgnoreCase("EmployeesView")){      System.out.println("This row is an employee: " +                          rw.getAttribute("EmployeeId"));     }        else{       System.out.println("Huh????");     }     // ... do more useful stuff here   } } -------------------- Download JDeveloper 11.1.2.1 Sample Workspace

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  • Usage of repository between EF model and code consumer

    - by jim
    I have binary data in my database that I'll have to convert to bitmap at some point. I was thinking whether or not it's appropriate to use a repository and do it there. My consumer, which is a presentation layer, will use this repository. For example: // This is a class I created for modeling the item as is. public class RealItem { public string Name { get; set; } public Bitmap Image { get; set; } } public abstract class BaseRepository { //using Unity (http://unity.codeplex.com) to inject the dependancy of entity context. [Dependency] public Context { get; set; } } public calss ItemRepository : BaseRepository { public List<Items> Select() { IEnumerable<Items> items = from item in Context.Items select item; List<RealItem> lst = new List<RealItem>(); foreach(itm in items) { MemoryStream stream = new MemoryStream(itm.Image); Bitmap image = (Bitmap)Image.FromStream(stream); RealItem ritem = new RealItem{ Name=item.Name, Image=image }; lst.Add(ritem); } return lst; } } Is this a correct way to use the repository pattern? I'm learning this pattern and I've seen a lot of examples online that are using a repository but when I looked at their source code... for example: public IQueryable<object> Select { return from q in base.Context select q; } as you can see no behavior is added to the system by their approach, so I was confused that maybe repository is something else and I got it all wrong. At the end there should be extra benifits of using them right?

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  • Building Queries Systematically

    - by Jeremy Smyth
    The SQL language is a bit like a toolkit for data. It consists of lots of little fiddly bits of syntax that, taken together, allow you to build complex edifices and return powerful results. For the uninitiated, the many tools can be quite confusing, and it's sometimes difficult to decide how to go about the process of building non-trivial queries, that is, queries that are more than a simple SELECT a, b FROM c; A System for Building Queries When you're building queries, you could use a system like the following:  Decide which fields contain the values you want to use in our output, and how you wish to alias those fields Values you want to see in your output Values you want to use in calculations . For example, to calculate margin on a product, you could calculate price - cost and give it the alias margin. Values you want to filter with. For example, you might only want to see products that weigh more than 2Kg or that are blue. The weight or colour columns could contain that information. Values you want to order by. For example you might want the most expensive products first, and the least last. You could use the price column in descending order to achieve that. Assuming the fields you've picked in point 1 are in multiple tables, find the connections between those tables Look for relationships between tables and identify the columns that implement those relationships. For example, The Orders table could have a CustomerID field referencing the same column in the Customers table. Sometimes the problem doesn't use relationships but rests on a different field; sometimes the query is looking for a coincidence of fact rather than a foreign key constraint. For example you might have sales representatives who live in the same state as a customer; this information is normally not used in relationships, but if your query is for organizing events where sales representatives meet customers, it's useful in that query. In such a case you would record the names of columns at either end of such a connection. Sometimes relationships require a bridge, a junction table that wasn't identified in point 1 above but is needed to connect tables you need; these are used in "many-to-many relationships". In these cases you need to record the columns in each table that connect to similar columns in other tables. Construct a join or series of joins using the fields and tables identified in point 2 above. This becomes your FROM clause. Filter using some of the fields in point 1 above. This becomes your WHERE clause. Construct an ORDER BY clause using values from point 1 above that are relevant to the desired order of the output rows. Project the result using the remainder of the fields in point 1 above. This becomes your SELECT clause. A Worked Example   Let's say you want to query the world database to find a list of countries (with their capitals) and the change in GNP, using the difference between the GNP and GNPOld columns, and that you only want to see results for countries with a population greater than 100,000,000. Using the system described above, we could do the following:  The Country.Name and City.Name columns contain the name of the country and city respectively.  The change in GNP comes from the calculation GNP - GNPOld. Both those columns are in the Country table. This calculation is also used to order the output, in descending order To see only countries with a population greater than 100,000,000, you need the Population field of the Country table. There is also a Population field in the City table, so you'll need to specify the table name to disambiguate. You can also represent a number like 100 million as 100e6 instead of 100000000 to make it easier to read. Because the fields come from the Country and City tables, you'll need to join them. There are two relationships between these tables: Each city is hosted within a country, and the city's CountryCode column identifies that country. Also, each country has a capital city, whose ID is contained within the country's Capital column. This latter relationship is the one to use, so the relevant columns and the condition that uses them is represented by the following FROM clause:  FROM Country JOIN City ON Country.Capital = City.ID The statement should only return countries with a population greater than 100,000,000. Country.Population is the relevant column, so the WHERE clause becomes:  WHERE Country.Population > 100e6  To sort the result set in reverse order of difference in GNP, you could use either the calculation, or the position in the output (it's the third column): ORDER BY GNP - GNPOld or ORDER BY 3 Finally, project the columns you wish to see by constructing the SELECT clause: SELECT Country.Name AS Country, City.Name AS Capital,        GNP - GNPOld AS `Difference in GNP`  The whole statement ends up looking like this:  mysql> SELECT Country.Name AS Country, City.Name AS Capital, -> GNP - GNPOld AS `Difference in GNP` -> FROM Country JOIN City ON Country.Capital = City.ID -> WHERE Country.Population > 100e6 -> ORDER BY 3 DESC; +--------------------+------------+-------------------+ | Country            | Capital    | Difference in GNP | +--------------------+------------+-------------------+ | United States | Washington | 399800.00 | | China | Peking | 64549.00 | | India | New Delhi | 16542.00 | | Nigeria | Abuja | 7084.00 | | Pakistan | Islamabad | 2740.00 | | Bangladesh | Dhaka | 886.00 | | Brazil | Brasília | -27369.00 | | Indonesia | Jakarta | -130020.00 | | Russian Federation | Moscow | -166381.00 | | Japan | Tokyo | -405596.00 | +--------------------+------------+-------------------+ 10 rows in set (0.00 sec) Queries with Aggregates and GROUP BY While this system might work well for many queries, it doesn't cater for situations where you have complex summaries and aggregation. For aggregation, you'd start with choosing which columns to view in the output, but this time you'd construct them as aggregate expressions. For example, you could look at the average population, or the count of distinct regions.You could also perform more complex aggregations, such as the average of GNP per head of population calculated as AVG(GNP/Population). Having chosen the values to appear in the output, you must choose how to aggregate those values. A useful way to think about this is that every aggregate query is of the form X, Y per Z. The SELECT clause contains the expressions for X and Y, as already described, and Z becomes your GROUP BY clause. Ordinarily you would also include Z in the query so you see how you are grouping, so the output becomes Z, X, Y per Z.  As an example, consider the following, which shows a count of  countries and the average population per continent:  mysql> SELECT Continent, COUNT(Name), AVG(Population)     -> FROM Country     -> GROUP BY Continent; +---------------+-------------+-----------------+ | Continent     | COUNT(Name) | AVG(Population) | +---------------+-------------+-----------------+ | Asia          |          51 |   72647562.7451 | | Europe        |          46 |   15871186.9565 | | North America |          37 |   13053864.8649 | | Africa        |          58 |   13525431.0345 | | Oceania       |          28 |    1085755.3571 | | Antarctica    |           5 |          0.0000 | | South America |          14 |   24698571.4286 | +---------------+-------------+-----------------+ 7 rows in set (0.00 sec) In this case, X is the number of countries, Y is the average population, and Z is the continent. Of course, you could have more fields in the SELECT clause, and  more fields in the GROUP BY clause as you require. You would also normally alias columns to make the output more suited to your requirements. More Complex Queries  Queries can get considerably more interesting than this. You could also add joins and other expressions to your aggregate query, as in the earlier part of this post. You could have more complex conditions in the WHERE clause. Similarly, you could use queries such as these in subqueries of yet more complex super-queries. Each technique becomes another tool in your toolbox, until before you know it you're writing queries across 15 tables that take two pages to write out. But that's for another day...

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  • Use CompiledQuery.Compile to improve LINQ to SQL performance

    - by Michael Freidgeim
    After reading DLinq (Linq to SQL) Performance and in particular Part 4  I had a few questions. If CompiledQuery.Compile gives so much benefits, why not to do it for all Linq To Sql queries? Is any essential disadvantages of compiling all select queries? What are conditions, when compiling makes whose performance, for how much percentage? World be good to have default on application config level or on DBML level to specify are all select queries to be compiled? And the same questions about Entity Framework CompiledQuery Class. However in comments I’ve found answer  of the author ricom 6 Jul 2007 3:08 AM Compiling the query makes it durable. There is no need for this, nor is there any desire, unless you intend to run that same query many times. SQL provides regular select statements, prepared select statements, and stored procedures for a reason.  Linq now has analogs. Also from 10 Tips to Improve your LINQ to SQL Application Performance   If you are using CompiledQuery make sure that you are using it more than once as it is more costly than normal querying for the first time. The resulting function coming as a CompiledQuery is an object, having the SQL statement and the delegate to apply it.  And your delegate has the ability to replace the variables (or parameters) in the resulting query. However I feel that many developers are not informed enough about benefits of Compile. I think that tools like FxCop and Resharper should check the queries  and suggest if compiling is recommended. Related Articles for LINQ to SQL: MSDN How to: Store and Reuse Queries (LINQ to SQL) 10 Tips to Improve your LINQ to SQL Application Performance Related Articles for Entity Framework: MSDN: CompiledQuery Class Exploring the Performance of the ADO.NET Entity Framework - Part 1 Exploring the Performance of the ADO.NET Entity Framework – Part 2 ADO.NET Entity Framework 4.0: Making it fast through Compiled Query

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  • Only One GPU Detected in the Nvidia Quadra NVS 450

    - by Kyle Brandt
    I just built myself an new workstation and now only 2 of 3 monitors are working. I built the nvidia driver by downloading it and installing with ./Nvidia... Before when I ran nvidia-settings I saw two GPUs listed but now I only see one. Xorg Config (Not sure how I ended up with 3 devices in there): # nvidia-settings: X configuration file generated by nvidia-settings # nvidia-settings: version 256.35 (buildmeister@builder101) Wed Jun 16 19:25:39 PDT 2010 Section "ServerLayout" # Removed Option "Xinerama" "1" Identifier "Layout0" Screen 0 "Screen0" 0 0 Screen 1 "Screen1" RightOf "Screen0" InputDevice "Keyboard0" "CoreKeyboard" InputDevice "Mouse0" "CorePointer" Option "Xinerama" "0" EndSection Section "Files" EndSection Section "InputDevice" # generated from default Identifier "Mouse0" Driver "mouse" Option "Protocol" "auto" Option "Device" "/dev/psaux" Option "Emulate3Buttons" "no" Option "ZAxisMapping" "4 5" EndSection Section "InputDevice" # generated from default Identifier "Keyboard0" Driver "kbd" EndSection Section "Monitor" # HorizSync source: edid, VertRefresh source: edid Identifier "Monitor0" VendorName "Unknown" ModelName "DELL E207WFP" HorizSync 30.0 - 83.0 VertRefresh 56.0 - 75.0 Option "DPMS" EndSection Section "Monitor" # HorizSync source: edid, VertRefresh source: edid Identifier "Monitor1" VendorName "Unknown" ModelName "DELL E207WFP" HorizSync 30.0 - 83.0 VertRefresh 56.0 - 75.0 Option "DPMS" EndSection Section "Monitor" # HorizSync source: edid, VertRefresh source: edid Identifier "Monitor2" VendorName "Unknown" ModelName "DELL E207WFP" HorizSync 30.0 - 83.0 VertRefresh 56.0 - 75.0 Option "DPMS" EndSection Section "Device" Identifier "Device0" Driver "nvidia" VendorName "NVIDIA Corporation" BoardName "Quadro NVS 450" BusID "PCI:6:0:0" EndSection Section "Device" Identifier "Device1" Driver "nvidia" VendorName "NVIDIA Corporation" BoardName "Quadro NVS 450" BusID "PCI:5:0:0" EndSection Section "Device" Identifier "Device2" Driver "nvidia" VendorName "NVIDIA Corporation" BoardName "Quadro NVS 450" BusID "PCI:3:0:0" EndSection Section "Screen" # Removed Option "TwinView" "0" # Removed Option "metamodes" "DFP-0: nvidia-auto-select +0+0" # Removed Option "metamodes" "DFP-0: nvidia-auto-select +0+275, DFP-3: nvidia-auto-select +1680+0" Identifier "Screen0" Device "Device0" Monitor "Monitor0" DefaultDepth 24 Option "TwinView" "1" Option "TwinViewXineramaInfoOrder" "DFP-3" Option "metamodes" "DFP-0: nvidia-auto-select +0+0, DFP-3: nvidia-auto-select +1680+0" SubSection "Display" Depth 24 EndSubSection EndSection Section "Screen" # Removed Option "metamodes" "DFP-3: nvidia-auto-select +0+0" Identifier "Screen1" Device "Device1" Monitor "Monitor1" DefaultDepth 24 Option "TwinView" "0" Option "metamodes" "nvidia-auto-select +0+0" SubSection "Display" Depth 24 EndSubSection EndSection Section "Screen" Identifier "Screen2" Device "Device2" Monitor "Monitor2" DefaultDepth 24 Option "TwinView" "0" Option "metamodes" "nvidia-auto-select +0+0" SubSection "Display" Depth 24 EndSubSection EndSection lscpi: 00:00.0 Host bridge: Intel Corporation 5520/5500/X58 I/O Hub to ESI Port (rev 13) 00:01.0 PCI bridge: Intel Corporation 5520/5500/X58 I/O Hub PCI Express Root Port 1 (rev 13) 00:02.0 PCI bridge: Intel Corporation 5520/5500/X58 I/O Hub PCI Express Root Port 2 (rev 13) 00:03.0 PCI bridge: Intel Corporation 5520/5500/X58 I/O Hub PCI Express Root Port 3 (rev 13) 00:10.0 PIC: Intel Corporation 5520/5500/X58 Physical and Link Layer Registers Port 0 (rev 13) 00:10.1 PIC: Intel Corporation 5520/5500/X58 Routing and Protocol Layer Registers Port 0 (rev 13) 00:11.0 PIC: Intel Corporation 5520/5500 Physical and Link Layer Registers Port 1 (rev 13) 00:11.1 PIC: Intel Corporation 5520/5500 Routing & Protocol Layer Register Port 1 (rev 13) 00:13.0 PIC: Intel Corporation 5520/5500/X58 I/O Hub I/OxAPIC Interrupt Controller (rev 13) 00:14.0 PIC: Intel Corporation 5520/5500/X58 I/O Hub System Management Registers (rev 13) 00:14.1 PIC: Intel Corporation 5520/5500/X58 I/O Hub GPIO and Scratch Pad Registers (rev 13) 00:14.2 PIC: Intel Corporation 5520/5500/X58 I/O Hub Control Status and RAS Registers (rev 13) 00:15.0 PIC: Intel Corporation 5520/5500/X58 Trusted Execution Technology Registers (rev 13) 00:1a.0 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #4 00:1a.1 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #5 00:1a.2 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #6 00:1a.7 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB2 EHCI Controller #2 00:1b.0 Audio device: Intel Corporation 82801JI (ICH10 Family) HD Audio Controller 00:1c.0 PCI bridge: Intel Corporation 82801JI (ICH10 Family) PCI Express Root Port 1 00:1c.1 PCI bridge: Intel Corporation 82801JI (ICH10 Family) PCI Express Port 2 00:1c.3 PCI bridge: Intel Corporation 82801JI (ICH10 Family) PCI Express Root Port 4 00:1c.4 PCI bridge: Intel Corporation 82801JI (ICH10 Family) PCI Express Root Port 5 00:1d.0 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #1 00:1d.1 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #2 00:1d.2 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #3 00:1d.7 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB2 EHCI Controller #1 00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 90) 00:1f.0 ISA bridge: Intel Corporation 82801JIR (ICH10R) LPC Interface Controller 00:1f.2 IDE interface: Intel Corporation 82801JI (ICH10 Family) 4 port SATA IDE Controller #1 00:1f.3 SMBus: Intel Corporation 82801JI (ICH10 Family) SMBus Controller 00:1f.5 IDE interface: Intel Corporation 82801JI (ICH10 Family) 2 port SATA IDE Controller #2 01:00.0 IDE interface: Device 1b4b:91a3 (rev 11) 02:00.0 USB Controller: NEC Corporation Device 0194 (rev 03) 03:00.0 PCI bridge: nVidia Corporation PCI express bridge for Quadro Plex S4 / Tesla S870 / Tesla S1070 (rev a3) 04:00.0 PCI bridge: nVidia Corporation PCI express bridge for Quadro Plex S4 / Tesla S870 / Tesla S1070 (rev a3) 04:02.0 PCI bridge: nVidia Corporation PCI express bridge for Quadro Plex S4 / Tesla S870 / Tesla S1070 (rev a3) 05:00.0 3D controller: nVidia Corporation G98 [Quadro NVS 450] (rev a1) 06:00.0 VGA compatible controller: nVidia Corporation G98 [Quadro NVS 450] (rev a1) 08:00.0 SATA controller: JMicron Technology Corp. JMB362/JMB363 Serial ATA Controller (rev 02) 08:00.1 IDE interface: JMicron Technology Corp. JMB362/JMB363 Serial ATA Controller (rev 02) 09:00.0 SATA controller: JMicron Technology Corp. JMB362/JMB363 Serial ATA Controller (rev 03) 09:00.1 IDE interface: JMicron Technology Corp. JMB362/JMB363 Serial ATA Controller (rev 03) 0a:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 06) 0b:06.0 FireWire (IEEE 1394): Texas Instruments TSB43AB23 IEEE-1394a-2000 Controller (PHY/Link)

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