Search Results

Search found 49224 results on 1969 pages for 'database mirroring sql se'.

Page 142/1969 | < Previous Page | 138 139 140 141 142 143 144 145 146 147 148 149  | Next Page >

• June 2013 release of SSDT contains a minor bug that you should be aware of

  - by jamiet

  I have discovered what seems, to me, like a bug in the June 2013 release of SSDT and given the problems that it created yesterday on my current gig I thought it prudent to write this blog post to inform people of it. I’ve built a very simple SSDT project to reproduce the problem that has just two tables, [Table1] and [Table2], and also a procedure [Procedure1]: The two tables have exactly the same definition, both a have a single column called [Id] of type integer. CREATE TABLE [dbo].[Table1] (     [Id] INT NOT NULL PRIMARY KEY ) My stored procedure simply joins the two together, orders them by the column used in the join predicate, and returns the results: CREATE PROCEDURE [dbo].[Procedure1] AS     SELECT t1.*     FROM    Table1 t1     INNER JOIN Table2 t2         ON    t1.Id = t2.Id     ORDER BY Id Now if I create those three objects manually and then execute the stored procedure, it works fine: So we know that the code works. Unfortunately, SSDT thinks that there is an error here: The text of that error is: Procedure: [dbo].[Procedure1] contains an unresolved reference to an object. Either the object does not exist or the reference is ambiguous because it could refer to any of the following objects: [dbo].[Table1].[Id] or [dbo].[Table2].[Id]. Its complaining that the [Id] field in the ORDER BY clause is ambiguous. Now you may well be thinking at this point “OK, just stick a table alias into the ORDER BY predicate and everything will be fine!” Well that’s true, but there’s a bigger problem here. One of the developers at my current client installed this drop of SSDT and all of a sudden all the builds started failing on his machine – he had errors left right and centre because, as it transpires, we have a fair bit of code that exhibits this scenario.  Worse, previous installations of SSDT do not flag this code as erroneous and therein lies the rub. We immediately had a mass panic where we had to run around the department to our developers (of which there are many) ensuring that none of them should upgrade their SSDT installation if they wanted to carry on being productive for the rest of the day. Also bear in mind that as soon as a new drop of SSDT comes out then the previous version is instantly unavailable so rolling back is going to be impossible unless you have created an administrative install of SSDT for that previous version. Just thought you should know! In the grand schema of things this isn’t a big deal as the bug can be worked around with a simple code modification but forewarned is forearmed so they say! Last thing to say, if you want to know which version of SSDT you are running check my blog post Which version of SSDT Database Projects do I have installed? @Jamiet

  Read the article

• Auditing DDL Changes in SQL Server databases

  Even where Source Control isn't being used by developers, it is still possible to automate the process of tracking the changes being made to a database and put those into Source Control, in order to track what changed and when. You can even get an email alert when it happens. With suitable scripting, you can even do it if you don't have direct access to the live database. Grant shows how easy this is with SQL Compare.

  Read the article

• ???????/???Web????????????!??????????????

  - by Yusuke.Yamamoto

  ????? ??:2010/11/04 ??:??????/?? ???????????????????·????????????????????????????????????????????????????????Web?????????????????????????????????????????????????????DB?? Oracle TimesTen In-Memory Database ???????????????????????????? ????????????????????????Oracle In-Memory Database Cache ?????Oracle TimesTen IMDB / Oracle IMDB Cache 11g ?????????? ????????? ????????????????? http://otndnld.oracle.co.jp/ondemand/otn-seminar/movie/TT11041100.wmv http://www.oracle.com/technology/global/jp/ondemand/otn-seminar/pdf/TimesTen_OrD_20101104_print.pdf

  Read the article

• .Net Windows Service Throws EventType clr20r3 system.data.sqlclient.sql error

  - by William Edmondson

  I have a .Net/c# 2.0 windows service. The entry point is wrapped in a try catch block yet when I look at the server's application event log I seem a number of "EventType clr20r3" errors that are causing the service to die unexpectedly. The catch block has a "catch (Exception ex)". Each sql commands is of the type "CommandType.StoredProcedure" and are executed with SqlDataReader's. These sproc calls function correctly 99% of time and have all been thoroughly unit tested, profiled, and QA'd. I additionally wrapped these calls in try catch blocks just to be sure and am still experiencing these unhandled exceptions. This only in our production environment and cannot be duplicated in our dev or staging environments (even under heavy load). Why would my error handling not catch this particular error? Is there anyway to capture more detail as to the root cause of the problem? Here is an example of the event log: EventType clr20r3, P1 RDC.OrderProcessorService, P2 1.0.0.0, P3 4ae6a0d0, P4 system.data, P5 2.0.0.0, P6 4889deaf, P7 2490, P8 2c, P9 system.data.sqlclient.sql, P10 NIL. Additionally The Order Processor service terminated unexpectedly. It has done this 1 time(s). The following corrective action will be taken in 60000 milliseconds: Restart the service.

  Read the article

• Error Handling in T-SQL Scalar Function

  - by hydroparadise

  Ok.. this question could easily take multiple paths, so I will hit the more specific path first. While working with SQL Server 2005, I'm trying to create a scalar funtion that acts as a 'TryCast' from varchar to int. Where I encounter a problem is when I add a TRY block in the function; CREATE FUNCTION u_TryCastInt ( @Value as VARCHAR(MAX) ) RETURNS Int AS BEGIN DECLARE @Output AS Int BEGIN TRY SET @Output = CONVERT(Int, @Value) END TRY BEGIN CATCH SET @Output = 0 END CATCH RETURN @Output END Turns out theres all sorts of things wrong with this statement including "Invalid use of side-effecting or time-dependent operator in 'BEGIN TRY' within a function" and "Invalid use of side-effecting or time-dependent operator in 'END TRY' within a function". I can't seem to find any examples of using try statements within a scalar function, which got me thinking, is error handling in a function is possible? The goal here is to make a robust version of the Convert or Cast functions to allow a SELECT statement carry through depsite conversion errors. For example, take the following; CREATE TABLE tblTest ( f1 VARCHAR(50) ) GO INSERT INTO tblTest(f1) VALUES('1') INSERT INTO tblTest(f1) VALUES('2') INSERT INTO tblTest(f1) VALUES('3') INSERT INTO tblTest(f1) VALUES('f') INSERT INTO tblTest(f1) VALUES('5') INSERT INTO tblTest(f1) VALUES('1.1') SELECT CONVERT(int,f1) AS f1_num FROM tblTest DROP TABLE tblTest It never reaches point of dropping the table because the execution gets hung on trying to convert 'f' to an integer. I want to be able to do something like this; SELECT u_TryCastInt(f1) AS f1_num FROM tblTest fi_num __________ 1 2 3 0 5 0 Any thoughts on this? Is there anything that exists that handles this? Also, I would like to try and expand the conversation to support SQL Server 2000 since Try blocks are not an option in that scenario. Thanks in advance.

  Read the article

• Complex SQL Query similar to a z order problem

  - by AaronLS

  I have a complex SQL problem in MS SQL Server, and in drawing on a piece of paper I realized that I could think of it as a single bar filled with rectangles, each rectangle having segments with different Z orders. In reality it has nothing to do with z order or graphics at all, but more to do with some complex business rules that would be difficult to explain. Howoever, if anyone has ideas on how to solve the below that will give me my solution. I have the following data: ObjectID, PercentOfBar, ZOrder (where smaller is closer) A, 100, 6 B, 50, 5 B, 50, 4 C, 30, 3 C, 70, 6 The result of my query that I want is this, in any order: PercentOfBar, ZOrder 50, 5 20, 4 30, 3 Think of it like this, if I drew rectangle A, it would fill 100% of the bar and have a z order of 6. 66666666666 AAAAAAAAAAA If I then layed out rectangle B, consisting of two segments, both segments would cover up rectangle A resulting in the following rendering: 4444455555 BBBBBBBBBB As a rule of thumb, for a given rectangle, it's segments should be layed out such that the highest z order is to the right of the lower Z orders. Finally rectangle C would cover up only portions of Rectangle B with it's 30% segment that is z order 3, which would be on the left. You can hopefully see how the is represented in the output dataset I listed above: 3334455555 CCCBBBBBBB Now to make things more complicated I actually have a 4th column such that this grouping occurs for each key: Input: SomeKey, ObjectID, PercentOfBar, ZOrder (where smaller is closer) X, A, 100, 6 X, B, 50, 5 X, B, 50, 4 X, C, 30, 3 X, C, 70, 6 Y, A, 100, 6 Z, B, 50, 2 Z, B, 50, 6 Z, C, 100, 5 Output: SomeKey, PercentOfBar, ZOrder X, 50, 5 X, 20, 4 X, 30, 3 Y, 100, 6 Z, 50, 2 Z, 50, 5 Notice in the output, the PercentOfBar for each SomeKey would add up to 100%. This is one I know I'm going to be thinking about when I go to bed tonight. Just to be explicit and have a question: What would be a query that would produce the results described above?

  Read the article

• Database design for summarized data

  - by holden

  I have a new table I'm going to add to a bunch of other summarized data, basically to take some of the load off by calculating weekly avgs. My question is whether I would be better off with one model over the other. One model with days of the week as a column with an additional column for price or another model as a series of fields for the DOW each taking a price. I'd like to know which would save me in speed and/or headaches? Or at least the trade off. IE. ID OBJECT_ID MON TUE WED THU FRI SAT SUN SOURCE OR ID OBJECT_ID DAYOFWEEK PRICE SOURCE

  Read the article

• Atomic UPSERT in SQL Server 2005

  - by rabidpebble

  What is the correct pattern for doing an atomic "UPSERT" (UPDATE where exists, INSERT otherwise) in SQL Server 2005? I see a lot of code on SO (e.g. see http://stackoverflow.com/questions/639854/tsql-check-if-a-row-exists-otherwise-insert) with the following two-part pattern: UPDATE ... FROM ... WHERE <condition> -- race condition risk here IF @@ROWCOUNT = 0 INSERT ... or IF (SELECT COUNT(*) FROM ... WHERE <condition>) = 0 -- race condition risk here INSERT ... ELSE UPDATE ... where will be an evaluation of natural keys. None of the above approaches seem to deal well with concurrency. If I cannot have two rows with the same natural key, it seems like all of the above risk inserting rows with the same natural keys in race condition scenarios. I have been using the following approach but I'm surprised not to see it anywhere in people's responses so I'm wondering what is wrong with it: INSERT INTO <table> SELECT <natural keys>, <other stuff...> FROM <table> WHERE NOT EXISTS -- race condition risk here? ( SELECT 1 FROM <table> WHERE <natural keys> ) UPDATE ... WHERE <natural keys> (Note: I'm assuming that rows will not be deleted from this table. Although it would be nice to discuss how to handle the case where they can be deleted -- are transactions the only option? Which level of isolation?) Is this atomic? I can't locate where this would be documented in SQL Server documentation.

  Read the article

• Fastest way to remove non-numeric characters from a VARCHAR in SQL Server

  - by Dan Herbert

  I'm writing an import utility that is using phone numbers as a unique key within the import. I need to check that the phone number does not already exist in my DB. The problem is that phone numbers in the DB could have things like dashes and parenthesis and possibly other things. I wrote a function to remove these things, the problem is that it is slow and with thousands of records in my DB and thousands of records to import at once, this process can be unacceptably slow. I've already made the phone number column an index. I tried using the script from this post: http://stackoverflow.com/questions/52315/t-sql-trim-nbsp-and-other-non-alphanumeric-characters But that didn't speed it up any. Is there a faster way to remove non-numeric characters? Something that can perform well when 10,000 to 100,000 records have to be compared. Whatever is done needs to perform fast. Update Given what people responded with, I think I'm going to have to clean the fields before I run the import utility. To answer the question of what I'm writing the import utility in, it is a C# app. I'm comparing BIGINT to BIGINT now, with no need to alter DB data and I'm still taking a performance hit with a very small set of data (about 2000 records). Could comparing BIGINT to BIGINT be slowing things down? I've optimized the code side of my app as much as I can (removed regexes, removed unneccessary DB calls). Although I can't isolate SQL as the source of the problem anymore, I still feel like it is.

  Read the article

• how many index per database table?

  - by sam

  Hi, How many indexes is preferred for one table in MYSQL?? I have a company table where I search mostly for ID,state and category? Thansk

  Read the article

• Can I select 0 columns in SQL Server?

  - by Woody Zenfell III

  I am hoping this question fares a little better than the similar Create a table without columns. Yes, I am asking about something that will strike most as pointlessly academic. It is easy to produce a SELECT result with 0 rows (but with columns), e.g. SELECT a = 1 WHERE 1 = 0. Is it possible to produce a SELECT result with 0 columns (but with rows)? e.g. something like SELECT NO COLUMNS FROM Foo. (This is not valid T-SQL.) I came across this because I wanted to insert several rows without specifying any column data for any of them. e.g. (SQL Server 2005) CREATE TABLE Bar (id INT NOT NULL IDENTITY PRIMARY KEY) INSERT INTO Bar SELECT NO COLUMNS FROM Foo -- Invalid column name 'NO'. -- An explicit value for the identity column in table 'Bar' can only be specified when a column list is used and IDENTITY_INSERT is ON. One can insert a single row without specifying any column data, e.g. INSERT INTO Foo DEFAULT VALUES. One can query for a count of rows (without retrieving actual column data from the table), e.g. SELECT COUNT(*) FROM Foo. (But that result set, of course, has a column.) I tried things like INSERT INTO Bar () SELECT * FROM Foo -- Parameters supplied for object 'Bar' which is not a function. -- If the parameters are intended as a table hint, a WITH keyword is required. and INSERT INTO Bar DEFAULT VALUES SELECT * FROM Foo -- which is a standalone INSERT statement followed by a standalone SELECT statement. I can do what I need to do a different way, but the apparent lack of consistency in support for degenerate cases surprises me. I read through the relevant sections of BOL and didn't see anything. I was surprised to come up with nothing via Google either.

  Read the article

• How to Convert using of SqlLit to Simple SQL command in C#

  - by Nasser Hajloo

  I want to get start with DayPilot control I do not use SQLLite and this control documented based on SQLLite. I want to use SQL instead of SQL Lite so if you can, please do this for me. main site with samples http://www.daypilot.org/calendar-tutorial.html The database contains a single table with the following structure CREATE TABLE event ( id VARCHAR(50), name VARCHAR(50), eventstart DATETIME, eventend DATETIME); Loading Events private DataTable dbGetEvents(DateTime start, int days) { SQLiteDataAdapter da = new SQLiteDataAdapter("SELECT [id], [name], [eventstart], [eventend] FROM [event] WHERE NOT (([eventend] <= @start) OR ([eventstart] >= @end))", ConfigurationManager.ConnectionStrings["db"].ConnectionString); da.SelectCommand.Parameters.AddWithValue("start", start); da.SelectCommand.Parameters.AddWithValue("end", start.AddDays(days)); DataTable dt = new DataTable(); da.Fill(dt); return dt; } Update private void dbUpdateEvent(string id, DateTime start, DateTime end) { using (SQLiteConnection con = new SQLiteConnection(ConfigurationManager.ConnectionStrings["db"].ConnectionString)) { con.Open(); SQLiteCommand cmd = new SQLiteCommand("UPDATE [event] SET [eventstart] = @start, [eventend] = @end WHERE [id] = @id", con); cmd.Parameters.AddWithValue("id", id); cmd.Parameters.AddWithValue("start", start); cmd.Parameters.AddWithValue("end", end); cmd.ExecuteNonQuery(); } }

  Read the article

• What does SQL Server's BACKUPIO wait type mean?

  - by solublefish

  I'm using Sql Server 2008 ("R1"), with some maintenance plans that back up my databases to a network share. Some of my backup jobs show long waits of type "BACKUPIO". Of course it seems like this is an I/O subsystem limitation, but I'm skeptical. Perfmon stats for I/O on the production (source) server are well within normal trends for that server. The destination server shows a sustained 7MB/s write rate, which seems incredibly low, even for a slow disk. The network link is gigabit ethernet and nowhere near saturated. The few docs I've turned up about BACKUPIO indicate that it's not specifically a wait on I/O, surprisingly enough. This MSFT doc says it's abnormal unless you're using a tape drive, which I'm not. But it doesn't say (or I don't understand) exactly what resource is missing. http://www.docstoc.com/docs/24580659/Performance-Tuning-in-SQL-Server-2005 And this piece says it's not related to I/O performance at all. http://www.informit.com/articles/article.aspx?p=686168&seqNum=5 "Note that BACKUPIO and IO_AUDIT_MUTEX are not related to IO performance." Anyway, does anyone know what BACKUPIO actually means and/or what I can do to diagnose or eliminate it?

  Read the article

• Implementing database redundancy with sharded tables

  - by ensnare

  We're looking to implement load balancing by horizontally sharding our tables across a cluster of servers. What are some options to implement live redundancy should a server fail? Would it be effective to do (2) INSERTS instead of one ... one to the target shard, and another to a secondary shard which could be accessed should the primary shard not respond? Or is there a better way? Thanks.

  Read the article

• Database warehouse design: fact tables and dimension tables

  - by morpheous

  I am building a poor man's data warehouse using a RDBMS. I have identified the key 'attributes' to be recorded as: sex (true/false) demographic classification (A, B, C etc) place of birth date of birth weight (recorded daily): The fact that is being recorded My requirements are to be able to run 'OLAP' queries that allow me to: 'slice and dice' 'drill up/down' the data and generally, be able to view the data from different perspectives After reading up on this topic area, the general consensus seems to be that this is best implemented using dimension tables rather than normalized tables. Assuming that this assertion is true (i.e. the solution is best implemented using fact and dimension tables), I would like to seek some help in the design of these tables. 'Natural' (or obvious) dimensions are: Date dimension Geographical location Which have hierarchical attributes. However, I am struggling with how to model the following fields: sex (true/false) demographic classification (A, B, C etc) The reason I am struggling with these fields is that: They have no obvious hierarchical attributes which will aid aggregation (AFAIA) - which suggest they should be in a fact table They are mostly static or very rarely change - which suggests they should be in a dimension table. Maybe the heuristic I am using above is too crude? I will give some examples on the type of analysis I would like to carryout on the data warehouse - hopefully that will clarify things further. I would like to aggregate and analyze the data by sex and demographic classification - e.g. answer questions like: How does male and female weights compare across different demographic classifications? Which demographic classification (male AND female), show the most increase in weight this quarter. etc. Can anyone clarify whether sex and demographic classification are part of the fact table, or whether they are (as I suspect) dimension tables.? Also assuming they are dimension tables, could someone elaborate on the table structures (i.e. the fields)? The 'obvious' schema: CREATE TABLE sex_type (is_male int); CREATE TABLE demographic_category (id int, name varchar(4)); may not be the correct one.

  Read the article

• database datatype size

  - by yeeen

  Just to clarify by specifying sth like VARCHAR(45) means it can take up to max 45 characters? I rmb I heard from someone a few years ago that the number in the parathesis doesn't refer to the no of characters, then the person tried to explain to me sth quite complicated which i don't understand n forgot alr. And what is the difference btn CHAR and VARCHAR? I did search ard a bit and see that CHAR gives u the max of the size of the column and it is better to use it if ur data has a fix size and use VARCHAR if ur data size varies. But if it gives u the max of the size of the column of all the data of this col, isn't it better to use it when ur data size varies? Esp if u don't know how big is ur data size gg to be. VARCHAR needs to specify the size (CHAR don't really need right?), isn't it more troublesome?

  Read the article

• SQL Server 2005 Reporting Services and the Report Viewer

  - by Kendra

  I am having an issue embedding my report into an aspx page. Here's my setup: 1 Server running SQL Server 2005 and SQL Server 2005 Reporting Services 1 Workstation running XP and VS 2005 The server is not on a domain. Reporting Services is a default installation. I have one report called TestMe in a folder called TestReports using a shared datasource. If I view the report in Report Manager, it renders fine. If I view the report using the http ://myserver/reportserver url it renders fine. If I view the report using the http ://myserver/reportserver?/TestReports/TestMe it renders fine. If I try to view the report using http ://myserver/reportserver/TestReports/TestMe, it just goes to the folder navigation page of the home directory. My web application is impersonating somebody specific to get around the server not being on a domain. When I call the report from the report viewer using http ://myserver/reportserver as the server and /TestReports/TestMe as the path I get this error: For security reasons DTD is prohibited in this XML document. To enable DTD processing set the ProhibitDtd property on XmlReaderSettings to false and pass the settings into XmlReader.Create method. When I change the server to http ://myserver/reportserver? I get this error when I run the report: Client found response content type of '', but expected 'text/xml'. The request failed with an empty response. I have been searching for a while and haven't found anything that fixes my issue. Please let me know if there is more information needed. Thanks in advance, Kendra

  Read the article

• SQL Query slow in .NET application but instantaneous in SQL Server Management Studio

  - by user203882

  Here is the SQL SELECT tal.TrustAccountValue FROM TrustAccountLog AS tal INNER JOIN TrustAccount ta ON ta.TrustAccountID = tal.TrustAccountID INNER JOIN Users usr ON usr.UserID = ta.UserID WHERE usr.UserID = 70402 AND ta.TrustAccountID = 117249 AND tal.trustaccountlogid = ( SELECT MAX (tal.trustaccountlogid) FROM TrustAccountLog AS tal INNER JOIN TrustAccount ta ON ta.TrustAccountID = tal.TrustAccountID INNER JOIN Users usr ON usr.UserID = ta.UserID WHERE usr.UserID = 70402 AND ta.TrustAccountID = 117249 AND tal.TrustAccountLogDate < '3/1/2010 12:00:00 AM' ) Basicaly there is a Users table a TrustAccount table and a TrustAccountLog table. Users: Contains users and their details TrustAccount: A User can have multiple TrustAccounts. TrustAccountLog: Contains an audit of all TrustAccount "movements". A TrustAccount is associated with multiple TrustAccountLog entries. Now this query executes in milliseconds inside SQL Server Management Studio, but for some strange reason it takes forever in my C# app and even timesout (120s) sometimes. Here is the code in a nutshell. It gets called multiple times in a loop and the statement gets prepared. cmd.CommandTimeout = Configuration.DBTimeout; cmd.CommandText = "SELECT tal.TrustAccountValue FROM TrustAccountLog AS tal INNER JOIN TrustAccount ta ON ta.TrustAccountID = tal.TrustAccountID INNER JOIN Users usr ON usr.UserID = ta.UserID WHERE usr.UserID = @UserID1 AND ta.TrustAccountID = @TrustAccountID1 AND tal.trustaccountlogid = (SELECT MAX (tal.trustaccountlogid) FROM TrustAccountLog AS tal INNER JOIN TrustAccount ta ON ta.TrustAccountID = tal.TrustAccountID INNER JOIN Users usr ON usr.UserID = ta.UserID WHERE usr.UserID = @UserID2 AND ta.TrustAccountID = @TrustAccountID2 AND tal.TrustAccountLogDate < @TrustAccountLogDate2 ))"; cmd.Parameters.Add("@TrustAccountID1", SqlDbType.Int).Value = trustAccountId; cmd.Parameters.Add("@UserID1", SqlDbType.Int).Value = userId; cmd.Parameters.Add("@TrustAccountID2", SqlDbType.Int).Value = trustAccountId; cmd.Parameters.Add("@UserID2", SqlDbType.Int).Value = userId; cmd.Parameters.Add("@TrustAccountLogDate2", SqlDbType.DateTime).Value =TrustAccountLogDate; // And then... reader = cmd.ExecuteReader(); if (reader.Read()) { double value = (double)reader.GetValue(0); if (System.Double.IsNaN(value)) return 0; else return value; } else return 0;

  Read the article

• SQL Server 2005 standard filegroups / files for performance on SAN

  - by Blootac

  Ok so I've just been on a SQL Server course and we discussed the usage scenarios of multiple filegroups and files when in use over local RAID and local disks but we didn't touch SAN scenarios so my question is as follows; I currently have a 250 gig database running on SQL Server 2005 where some tables have a huge number of writes and others are fairly static. The database and all objects reside in a single file group with a single data file. The log file is also on the same volume. My interpretation is that separate data files should be used across different disks to lessen disk contention and that file groups should be used for partitioning of data. However, with a SAN you obviously don't really have the same issue of disk contention that you do with a small RAID setup (or at least we don't at the moment), and standard edition doesn't support partitioning. So in order to improve parallelism what should I do? My understanding of various Microsoft publications is that if I increase the number of data files, separate threads can act across each file separately. Which leads me to the question how many files should I have. One per core? Should I be putting tables and indexes with high levels of activity in separate file groups, each with the same number of data files as we have cores? Thank you

  Read the article

• Database warehoue design: fact tables and dimension tables

  - by morpheous

  I am building a poor man's data warehouse using a RDBMS. I have identified the key 'attributes' to be recorded as: sex (true/false) demographic classification (A, B, C etc) place of birth date of birth weight (recorded daily): The fact that is being recorded My requirements are to be able to run 'OLAP' queries that allow me to: 'slice and dice' 'drill up/down' the data and generally, be able to view the data from different perspectives After reading up on this topic area, the general consensus seems to be that this is best implemented using dimension tables rather than normalized tables. Assuming that this assertion is true (i.e. the solution is best implemented using fact and dimension tables), I would like to see some help in the design of these tables. 'Natural' (or obvious) dimensions are: Date dimension Geographical location Which have hierarchical attributes. However, I am struggling with how to model the following fields: sex (true/false) demographic classification (A, B, C etc) The reason I am struggling with these fields is that: They have no obvious hierarchical attributes which will aid aggregation (AFAIA) - which suggest they should be in a fact table They are mostly static or very rarely change - which suggests they should be in a dimension table. Maybe the heuristic I am using above is too crude? I will give some examples on the type of analysis I would like to carryout on the data warehouse - hopefully that will clarify things further. I would like to aggregate and analyze the data by sex and demographic classification - e.g. answer questions like: How does male and female weights compare across different demographic classifications? Which demographic classification (male AND female), show the most increase in weight this quarter. etc. Can anyone clarify whether sex and demographic classification are part of the fact table, or whether they are (as I suspect) dimension tables.? Also assuming they are dimension tables, could someone elaborate on the table structures (i.e. the fields)? The 'obvious' schema: CREATE TABLE sex_type (is_male int); CREATE TABLE demographic_category (id int, name varchar(4)); may not be the correct one.

  Read the article

• Is it easy to switch from relational to non-relational databases with Rails?

  - by Tam

  Good day, I have been using Rails/Mysql for the past while but I have been hearing about Cassandra, MongoDB, CouchDB and other document-store DB/Non-relational databases. I'm planning to explore them later as they might be better alternative for scalability. I'm planning to start an application soon. Will it make a different with Rails design if I move from relational to non-relational database? I know Rails migrations are database-agnostic but wasn't sure if moving to non-relational will make difference with design or not.

  Read the article

• database design to speed up hibernate querying of large dataset

  - by paddydub

  I currently have the below tables representing a bus network mapped in hibernate, accessed from a Spring MVC based bus route planner I'm trying to make my route planner application perform faster, I load all the above tables into Lists to perform the route planner logic. I would appreciate if anyone has any ideas of how to speed my performace Or any suggestions of another method to approach this problem of handling a large set of data Coordinate Connections Table (INT,INT,INT)( Containing 50,000 Coordinate Connections) ID, FROMCOORDID, TOCOORDID 1 1 2 2 1 17 3 1 63 4 1 64 5 1 65 6 1 95 Coordinate Table (INT,DECIMAL, DECIMAL) (Containing 4700 Coordinates) ID , LAT, LNG 0 59.352669 -7.264341 1 59.352669 -7.264341 2 59.350012 -7.260653 3 59.337585 -7.189798 4 59.339221 -7.193582 5 59.341408 -7.205888 Bus Stop Table (INT, INT, INT)(Containing 15000 Stops) StopID RouteID COORDINATEID 1000100001 100 17 1000100002 100 18 1000100003 100 19 1000100004 100 20 1000100005 100 21 1000100006 100 22 1000100007 100 23 This is how long it takes to load all the data from each table: stop.findAll = 148ms, stops.size: 15670 Hibernate: select coordinate0_.COORDINATEID as COORDINA1_2_, coordinate0_.LAT as LAT2_, coordinate0_.LNG as LNG2_ from COORDINATES coordinate0_ coord.findAll = 51ms , coordinates.size: 4704 Hibernate: select coordconne0_.COORDCONNECTIONID as COORDCON1_3_, coordconne0_.DISTANCE as DISTANCE3_, coordconne0_.FROMCOORDID as FROMCOOR3_3_, coordconne0_.TOCOORDID as TOCOORDID3_ from COORDCONNECTIONS coordconne0_ coordinateConnectionDao.findAll = 238ms ; coordConnectioninates.size:48132 Hibernate Annotations @Entity @Table(name = "STOPS") public class Stop implements Serializable { @Id @GeneratedValue @Column(name = "COORDINATEID") private Integer CoordinateID; @Column(name = "LAT") private double latitude; @Column(name = "LNG") private double longitude; } @Table(name = "COORDINATES") public class Coordinate { @Id @GeneratedValue @Column(name = "COORDINATEID") private Integer CoordinateID; @Column(name = "LAT") private double latitude; @Column(name = "LNG") private double longitude; } @Entity @Table(name = "COORDCONNECTIONS") public class CoordConnection { @Id @GeneratedValue @Column(name = "COORDCONNECTIONID") private Integer CoordinateID; /** * From Coordinate_id value */ @Column(name = "FROMCOORDID", nullable = false) private int fromCoordID; /** * To Coordinate_id value */ @Column(name = "TOCOORDID", nullable = false) private int toCoordID; //private Coordinate toCoordID; }

  Read the article

• SQL Where Clause Against View

  - by Adam Carr

  I have a view (actually, it's a table valued function, but the observed behavior is the same in both) that inner joins and left outer joins several other tables. When I query this view with a where clause similar to SELECT * FROM [v_MyView] WHERE [Name] like '%Doe, John%' ... the query is very slow, but if I do the following... SELECT * FROM [v_MyView] WHERE [ID] in ( SELECT [ID] FROM [v_MyView] WHERE [Name] like '%Doe, John%' ) it is MUCH faster. The first query is taking at least 2 minutes to return, if not longer where the second query will return in less than 5 seconds. Any suggestions on how I can improve this? If I run the whole command as one SQL statement (without the use of a view) it is very fast as well. I believe this result is because of how a view should behave as a table in that if a view has OUTER JOINS, GROUP BYS or TOP ##, if the where clause was interpreted prior to vs after the execution of the view, the results could differ. My question is why wouldn't SQL optimize my first query to something as efficient as my second query?

  Read the article

• Database Design Primay Key, ID vs String

  - by LnDCobra

  Hi, I am currently planning to develop a music streaming application. And i am wondering what would be better as a primary key in my tables on the server. An ID int or a Unique String. Methods 1: Songs Table: SongID(int), Title(string), Artist*(string), Length(int), Album*(string) Genre Table Genre(string), Name(string) SongGenre: SongID*(int), Genre*(string) Method 2 Songs Table: SongID(int), Title(string), ArtistID*(int), Length(int), AlbumID*(int) Genre Table GenreID(int), Name(string) SongGenre: SongID*(int), GenreID*(int) Key: Bold = Primary Key, Field* = Foreign Key I'm currently designing using method 2 as I believe it will speed up lookup performance and use less space as an int takes a lot less space then a string. Is there any reason this isn't a good idea? Is there anything I should be aware of?

  Read the article

• SQL Server Clustered Index: (Physical) Data Page Order

  - by scherand

  I am struggling understanding what a clustered index in SQL Server 2005 is. I read the MSDN article Clustered Index Structures (among other things) but I am still unsure if I understand it correctly. The (main) question is: what happens if I insert a row (with a "low" key) into a table with a clustered index? The above mentioned MSDN article states: The pages in the data chain and the rows in them are ordered on the value of the clustered index key. And Using Clustered Indexes for example states: For example, if a record is added to the table that is close to the beginning of the sequentially ordered list, any records in the table after that record will need to shift to allow the record to be inserted. Does this mean that if I insert a row with a very "low" key into a table that already contains a gazillion rows literally all rows are physically shifted on disk? I cannot believe that. This would take ages, no? Or is it rather (as I suspect) that there are two scenarios depending on how "full" the first data page is. A) If the page has enough free space to accommodate the record it is placed into the existing data page and data might be (physically) reordered within that page. B) If the page does not have enough free space for the record a new data page would be created (anywhere on the disk!) and "linked" to the front of the leaf level of the B-Tree? This would then mean the "physical order" of the data is restricted to the "page level" (i.e. within a data page) but not to the pages residing on consecutive blocks on the physical hard drive. The data pages are then just linked together in the correct order. Or formulated in an alternative way: if SQL Server needs to read the first N rows of a table that has a clustered index it can read data pages sequentially (following the links) but these pages are not (necessarily) block wise in sequence on disk (so the disk head has to move "randomly"). How close am I? :)

  Read the article

< Previous Page | 138 139 140 141 142 143 144 145 146 147 148 149  | Next Page >