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  • SQL SERVER – Disabled Index and Update Statistics

    - by pinaldave
    When we try to update the statistics, it throws an error as if the clustered index is disabled. Now let us enable the clustered index only and attempt to update the statistics of the table right after that. Have you ever come across the situation where a conversation never gets over and it continues even though original point of discussion has passed. I am facing the same situation in the case of Disabled Index. Here is the link to original conversations. SQL SERVER – Disable Clustered Index and Data Insert – Reader had a issue here with Disabled Index SQL SERVER – Understanding ALTER INDEX ALL REBUILD with Disabled Clustered Index – Reader asked the effect of Rebuilding Indexes The same reader asked me today – “I understood what the disabled indexes do; what is their effect on statistics. Is it true that even though indexes are disabled, they continue updating the statistics?“ The answer is very interesting: If you have disabled clustered index, you will be not able to update the statistics at all for any index. If you have enabled clustered index and disabled non clustered index when you update the statistics of the table, it automatically updates the statistics of the ALL (disabled and enabled – both) the indexes on the table. If you are not satisfied with the answer, let us go over a simple example. I have written necessary comments in the code itself to have a clear idea. USE tempdb GO -- Drop Table if Exists IF EXISTS (SELECT * FROM sys.objects WHERE OBJECT_ID = OBJECT_ID(N'[dbo].[TableName]') AND type IN (N'U')) DROP TABLE [dbo].[TableName] GO -- Create Table CREATE TABLE [dbo].[TableName]( [ID] [int] NOT NULL, [FirstCol] [varchar](50) NULL ) GO -- Insert Some data INSERT INTO TableName SELECT 1, 'First' UNION ALL SELECT 2, 'Second' UNION ALL SELECT 3, 'Third' UNION ALL SELECT 4, 'Fourth' UNION ALL SELECT 5, 'Five' GO -- Create Clustered Index ALTER TABLE [TableName] ADD CONSTRAINT [PK_TableName] PRIMARY KEY CLUSTERED ([ID] ASC) GO -- Create Nonclustered Index CREATE UNIQUE NONCLUSTERED INDEX [IX_NonClustered_TableName] ON [dbo].[TableName] ([FirstCol] ASC) GO -- Check that all the indexes are enabled SELECT OBJECT_NAME(OBJECT_ID), Name, type_desc, is_disabled FROM sys.indexes WHERE OBJECT_NAME(OBJECT_ID) = 'TableName' GO Now let us update the statistics of the table and check the statistics update date. -- Update the stats of table UPDATE STATISTICS TableName WITH FULLSCAN GO -- Check Statistics Last Updated Datetime SELECT name AS index_name, STATS_DATE(OBJECT_ID, index_id) AS StatsUpdated FROM sys.indexes WHERE OBJECT_ID = OBJECT_ID('TableName') GO Now let us disable the indexes and check if they are disabled using sys.indexes. -- Disable Indexes -- Disable Nonclustered Index ALTER INDEX [IX_NonClustered_TableName] ON [dbo].[TableName] DISABLE GO -- Disable Clustered Index ALTER INDEX [PK_TableName] ON [dbo].[TableName] DISABLE GO -- Check that all the indexes are disabled SELECT OBJECT_NAME(OBJECT_ID), Name, type_desc, is_disabled FROM sys.indexes WHERE OBJECT_NAME(OBJECT_ID) = 'TableName' GO Let us try to update the statistics of the table. -- Update the stats of table UPDATE STATISTICS TableName WITH FULLSCAN GO /* -- Above operation should thrown following error Msg 1974, Level 16, State 1, Line 1 Cannot perform the specified operation on table 'TableName' because its clustered index 'PK_TableName' is disabled. */ When we try to update the statistics it throws an error as it clustered index is disabled. Now let us enable the clustered index only and attempt to update the statistics of the table right after that. -- Now let us rebuild clustered index only ALTER INDEX [PK_TableName] ON [dbo].[TableName] REBUILD GO -- Check that all the indexes status SELECT OBJECT_NAME(OBJECT_ID), Name, type_desc, is_disabled FROM sys.indexes WHERE OBJECT_NAME(OBJECT_ID) = 'TableName' GO -- Check Statistics Last Updated Datetime SELECT name AS index_name, STATS_DATE(OBJECT_ID, index_id) AS StatsUpdated FROM sys.indexes WHERE OBJECT_ID = OBJECT_ID('TableName') GO -- Update the stats of table UPDATE STATISTICS TableName WITH FULLSCAN GO -- Check Statistics Last Updated Datetime SELECT name AS index_name, STATS_DATE(OBJECT_ID, index_id) AS StatsUpdated FROM sys.indexes WHERE OBJECT_ID = OBJECT_ID('TableName') GO We can clearly see that even though the nonclustered index is disabled it is also updated. If you do not need a nonclustered index, I suggest you to drop it as keeping them disabled is an overhead on your system. This is because every time the statistics are updated for system all the statistics for disabled indexesare also updated. -- Clean up DROP TABLE [TableName] GO The complete script is given below for easy reference. USE tempdb GO -- Drop Table if Exists IF EXISTS (SELECT * FROM sys.objects WHERE OBJECT_ID = OBJECT_ID(N'[dbo].[TableName]') AND type IN (N'U')) DROP TABLE [dbo].[TableName] GO -- Create Table CREATE TABLE [dbo].[TableName]( [ID] [int] NOT NULL, [FirstCol] [varchar](50) NULL ) GO -- Insert Some data INSERT INTO TableName SELECT 1, 'First' UNION ALL SELECT 2, 'Second' UNION ALL SELECT 3, 'Third' UNION ALL SELECT 4, 'Fourth' UNION ALL SELECT 5, 'Five' GO -- Create Clustered Index ALTER TABLE [TableName] ADD CONSTRAINT [PK_TableName] PRIMARY KEY CLUSTERED ([ID] ASC) GO -- Create Nonclustered Index CREATE UNIQUE NONCLUSTERED INDEX [IX_NonClustered_TableName] ON [dbo].[TableName] ([FirstCol] ASC) GO -- Check that all the indexes are enabled SELECT OBJECT_NAME(OBJECT_ID), Name, type_desc, is_disabled FROM sys.indexes WHERE OBJECT_NAME(OBJECT_ID) = 'TableName' GO -- Update the stats of table UPDATE STATISTICS TableName WITH FULLSCAN GO -- Check Statistics Last Updated Datetime SELECT name AS index_name, STATS_DATE(OBJECT_ID, index_id) AS StatsUpdated FROM sys.indexes WHERE OBJECT_ID = OBJECT_ID('TableName') GO -- Disable Indexes -- Disable Nonclustered Index ALTER INDEX [IX_NonClustered_TableName] ON [dbo].[TableName] DISABLE GO -- Disable Clustered Index ALTER INDEX [PK_TableName] ON [dbo].[TableName] DISABLE GO -- Check that all the indexes are disabled SELECT OBJECT_NAME(OBJECT_ID), Name, type_desc, is_disabled FROM sys.indexes WHERE OBJECT_NAME(OBJECT_ID) = 'TableName' GO -- Update the stats of table UPDATE STATISTICS TableName WITH FULLSCAN GO /* -- Above operation should thrown following error Msg 1974, Level 16, State 1, Line 1 Cannot perform the specified operation on table 'TableName' because its clustered index 'PK_TableName' is disabled. */ -- Now let us rebuild clustered index only ALTER INDEX [PK_TableName] ON [dbo].[TableName] REBUILD GO -- Check that all the indexes status SELECT OBJECT_NAME(OBJECT_ID), Name, type_desc, is_disabled FROM sys.indexes WHERE OBJECT_NAME(OBJECT_ID) = 'TableName' GO -- Check Statistics Last Updated Datetime SELECT name AS index_name, STATS_DATE(OBJECT_ID, index_id) AS StatsUpdated FROM sys.indexes WHERE OBJECT_ID = OBJECT_ID('TableName') GO -- Update the stats of table UPDATE STATISTICS TableName WITH FULLSCAN GO -- Check Statistics Last Updated Datetime SELECT name AS index_name, STATS_DATE(OBJECT_ID, index_id) AS StatsUpdated FROM sys.indexes WHERE OBJECT_ID = OBJECT_ID('TableName') GO -- Clean up DROP TABLE [TableName] GO Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Index, SQL Optimization, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: SQL Statistics

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  • where is the best place to place a javascript snippet to alter the DOM of a page before it renders

    - by icepack
    I have a few dynamic pages and I want to alter certain elements before the page has fully rendered. My snippet is something like document.body.getElementById("change").innerHTML = "<img src..."; I do not have access to change the content server side. Where is the best place to put the snippet to have the code run before the page it has rendered? Rather, is putting the javascript in either the HEAD (inside the window.onload event?) or before the closing BODY(not inside an event listener) optimal?

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  • How to Not alter font in webpage after opening a file (pdf or jpg) in ASP.NET C#? [closed]

    - by Victor
    Possible Duplicate: How to not alter font in webpage after opening a pdf in ASP.NET C#? Previously I posted this question: How to open files from a specific route in ASP-NET c#? in fact, I have already asked this however it was only a minor question so I guess it wasn't that important in the previous post, so I will ask here. Whenever I open a pdf with: Response.Write("<script>window.open('FilePath');</script>"); All of the font in the page is altered, example, the letter's size increases and some of the letter's colors are switched to black instead of the font that I assigned. Is there a way that I can work around that?? http://imageshack.us/a/img838/5145/beforeja.png http://imageshack.us/a/img546/4760/afterw.png Oh and I noticed that this also happens when you open images like jpg

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  • referencing part of the composite primary key

    - by Zavael
    I have problems with setting the reference on database table. I have following structure: CREATE TABLE club( id INTEGER NOT NULL, name_short VARCHAR(30), name_full VARCHAR(70) NOT NULL ); CREATE UNIQUE INDEX club_uix ON club(id); ALTER TABLE club ADD CONSTRAINT club_pk PRIMARY KEY (id); CREATE TABLE team( id INTEGER NOT NULL, club_id INTEGER NOT NULL, team_name VARCHAR(30) ); CREATE UNIQUE INDEX team_uix ON team(id, club_id); ALTER TABLE team ADD CONSTRAINT team_pk PRIMARY KEY (id, club_id); ALTER TABLE team ADD FOREIGN KEY (club_id) REFERENCES club(id); CREATE TABLE person( id INTEGER NOT NULL, first_name VARCHAR(20), last_name VARCHAR(20) NOT NULL ); CREATE UNIQUE INDEX person_uix ON person(id); ALTER TABLE person ADD PRIMARY KEY (id); CREATE TABLE contract( person_id INTEGER NOT NULL, club_id INTEGER NOT NULL, wage INTEGER ); CREATE UNIQUE INDEX contract_uix on contract(person_id); ALTER TABLE contract ADD CONSTRAINT contract_pk PRIMARY KEY (person_id); ALTER TABLE contract ADD FOREIGN KEY (club_id) REFERENCES club(id); ALTER TABLE contract ADD FOREIGN KEY (person_id) REFERENCES person(id); CREATE TABLE player( person_id INTEGER NOT NULL, team_id INTEGER, height SMALLINT, weight SMALLINT ); CREATE UNIQUE INDEX player_uix on player(person_id); ALTER TABLE player ADD CONSTRAINT player_pk PRIMARY KEY (person_id); ALTER TABLE player ADD FOREIGN KEY (person_id) REFERENCES person(id); -- ALTER TABLE player ADD FOREIGN KEY (team_id) REFERENCES team(id); --this is not working It gives me this error: Error code -5529, SQL state 42529: a UNIQUE constraint does not exist on referenced columns: TEAM in statement [ALTER TABLE player ADD FOREIGN KEY (team_id) REFERENCES team(id)] As you can see, team table has composite primary key (club_id + id), the person references club through contract. Person has some common attributes for player and other staff types. One club can have multiple teams. Employed person has to have a contract with a club. Player (is the specification of person) - if emplyed - can be assigned to one of the club's teams. Is there better way to design my structure? I thought about excluding the club_id from team's primary key, but I would like to know if this is the only way. Thanks. UPDATE 1 I would like to have the id as team identification only within the club, so multiple teams can have equal id as long as they belong to different clubs. Is it possible? UPDATE 2 updated the naming convention as adviced by philip Some business rules to better understand the structure: One club can have 1..n teams (Main squad, Reserve squad, Youth squad or Team A, Team B... only team can play match, not club) One team belongs to one club only A player is type of person (other types (staff) are scouts, coaches etc so they do not need to belong to specific team, just to the club, if employed) Person can have 0..1 contract with 1 club (that means he is employed or unemployed) Player (if employed) belongs to one team of the club Now thinking about it - moving team_id from player to contract would solve my problem, and it could hold the condition "Player (if employed) belongs to one team of the club", but it would be redundant for other staff types. What do you think?

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  • How can I alter an external variable from inside my AJAX?

    - by tmedge
    I keep on having these same two problems. I have been trying to use Remy Sharp's wonderful tagSuggest plugin, and it works great. Until I try to use an AJAX call to get tags from my database. My setGlobalTags() works great, with my defined myTagList at the top of the function. What I want to do is set myTagList equal to the result from my AJAX. My problem is that I can neither call setGlobalTags() from inside my success or error functions, nor actually alter the original myTagList. Also, I keep on having this other issue as well. I keep this code in my Master page, and my AJAX returns 'success' on almost every page. I only (and always) get the error alert when I navigate to a page that actually contains something of id="ParentTags". I don't see why this is happening, because my $('#ParentTags').tagSuggest(); is definitely after my AJAX call. I realize that this is probably just some dumb conventions error, but I am new to this and I'm here to learn from you guys. Thanks in advance! $(function() { var myTagList = ['test', 'testMore', 'testALot']; $.ajax({ type: "POST", url: 'Admin/GetTagList', dataType: 'json', success: function(resultTags) { myTagList = resultTags; alert(myTagList[0]); setGlobalTags(myTagList); }, error: function() { alert('Error'); setGlobalTags(myTagList); } }); setGlobalTags(myTagList); $('#ParentTags').tagSuggest(); });

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  • Roughly how long should an "ALTER TABLE" take on an 1.3GB INNODB table?

    - by justkevin
    I'm trying to optimize a table that hasn't been optimized in a long time. It has around 2.5 million rows with 1.3 GB of data and a 152 MB index. I started optimizing it about 15 minutes ago and I have no idea how long it will take. The server is reasonably robust (quad xeon with 4GB ram) and has a 500MB innodb buffer pool size. Should I expect this to take minutes, hours or days?

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  • T-SQL for autogrowth of multiple data files

    - by ddono25
    I can't seem to figure out the problems with my script to alter SQL Server 2008 database and file growth. There are two data files and a log file, all which need to have Autogrowth ON. Does this look completely wrong? Thanks! USE MASTER GO ALTER DATABASE BigDB MODIFY FILE ( NAME = BIGDBPPE, FILENAME = "H:\MSSQL\Data\BigDB.mdf", MAXSIZE = UNLIMITED, FILEGROWTH = 2000MB) USE MASTER GO ALTER DATABASE BigDB MODIFY FILE ( NAME = BIGDBPPE1, FILENAME = "K:\MSSQL\Data\BigDB_data1.ndf", MAXSIZE = UNLIMITED, FILEGROWTH = 2000MB) USE MASTER GO ALTER DATABASE BigDB MODIFY FILE ( NAME = BIGDBPPE_log, FILENAME = "O:\MSSQL\Data\BigDB_log.ldf", MAXSIZE = UNLIMITED, FILEGROWTH = 200MB) GO

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  • How to alter my mac os $PATH variable so that I can run the latest php version? [closed]

    - by skiabox
    Possible Duplicate: What are PATH and other environment variables, and how can I set or use them? I've just followed this article (http://mac.tutsplus.com/tutorials/server/upgrading-the-native-php-installation-on-os-x-mountain-lion/) to update my php installation using HomeBrew. The latest php version is indeed installed in /usr/local/bin The problem is that my $PATH variable is the following (doing an echo $PATH reveals it) : /usr/local/mysql/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/opt/X11/bin ...so the old version of php (that comes with mountain lion) always run first Any ideas on how to solve this? Thank you.

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  • Is there a way to alter Zend Studio PhpDoc preferences?

    - by Tower
    Hi, I'm trying out Zend Studio trial and I have a few things on my mind related to PhpDoc. If I have the following code: public function sum($a, $b) { echo $a + $b; } and then I start typing /** in the front of the function and press Enter, Zend Studio automatically makes the following text: /** * [cursor] * @param unknown_type $a * @param unknown_type $b */ However, I want to customize this so that it also includes @return void automatically since there's no return inside the function. Is there a way to do this? And what about things like @access? It's obviously "public". Another thing I want is that when I create a new file and I use the code templates with ${user}, it will use my Windows account, but I want it to use something else - is there a way to specify this "user"?

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  • Cannot create a row of size 8074 which is greater than the allowable maximum row size of 8060.

    - by Lieven Cardoen
    I have already asked a question about this, but the problems keeps on hitting me ;-) I have two tables that are identical. I want to add a xml column. In the first table this is no problem, but in the second table I get the sqlException (title). However, apart from the data in it, they are the same. So, can I get the sqlException because of data in the table? I have also tried to store the field off page with EXEC sp_tableoption 'dbo.PackageSessionNodesFinished', 'large value types out of row', 1 but without any succes. The same SqlException keeps coming. First table: PackageSessionNodes CREATE TABLE [dbo].[PackageSessionNodes]( [PackageSessionNodeId] [int] IDENTITY(1,1) NOT NULL, [PackageSessionId] [int] NOT NULL, [TreeNodeId] [int] NOT NULL, [Duration] [int] NULL, [Score] [float] NOT NULL, [ScoreMax] [float] NOT NULL, [Interactions] [xml] NOT NULL, [BrainTeaser] [bit] NULL, [DateCreated] [datetime] NULL, [CompletionStatus] [int] NOT NULL, [ReducedScore] [float] NOT NULL, [ReducedScoreMax] [float] NOT NULL, [ContentInteractions] [xml] NOT NULL, CONSTRAINT [PK_PackageSessionNodes] PRIMARY KEY CLUSTERED ( [PackageSessionNodeId] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] Second table: PackageSessionNodesFinished CREATE TABLE [dbo].[PackageSessionNodesFinished]( [PackageSessionNodeFinishedId] [int] IDENTITY(1,1) NOT NULL, [PackageSessionId] [int] NOT NULL, [TreeNodeId] [int] NOT NULL, [Duration] [int] NULL, [Score] [float] NOT NULL, [ScoreMax] [float] NOT NULL, [Interactions] [xml] NOT NULL, [BrainTeaser] [bit] NULL, [DateCreated] [datetime] NULL, [CompletionStatus] [int] NOT NULL, [ReducedScore] [float] NOT NULL, [ReducedScoreMax] [float] NOT NULL, [ContentInteractions] [xml] NULL, CONSTRAINT [PK_PackageSessionNodesFinished] PRIMARY KEY CLUSTERED ( [PackageSessionNodeFinishedId] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] First script I tried to run (First two ALTER TABLE work fine, the third crashes on SqlException) ALTER TABLE dbo.PackageSessionNodes ADD ContentInteractions xml NOT NULL CONSTRAINT DF_PackageSessionNodes_ContentInteractions DEFAULT (('<contentinteractions/>')); ALTER TABLE dbo.PackageSessionNodes DROP CONSTRAINT DF_PackageSessionNodes_ContentInteractions ALTER TABLE dbo.PackageSessionNodesFinished ADD ContentInteractions xml NOT NULL CONSTRAINT DF_PackageSessionNodesFinished_ContentInteractions DEFAULT (('<contentinteractions/>')); ALTER TABLE dbo.PackageSessionNodesFinished DROP CONSTRAINT DF_PackageSessionNodesFinished_ContentInteractions Second script I tried to run with the same result as previous script: EXEC sp_tableoption 'dbo.PackageSessionNodes', 'large value types out of row', 1 ALTER TABLE dbo.PackageSessionNodes ADD ContentInteractions xml NOT NULL CONSTRAINT DF_PackageSessionNodes_ContentInteractions DEFAULT (('<contentinteractions/>')); ALTER TABLE dbo.PackageSessionNodes DROP CONSTRAINT DF_PackageSessionNodes_ContentInteractions EXEC sp_tableoption 'dbo.PackageSessionNodesFinished', 'large value types out of row', 1 ALTER TABLE dbo.PackageSessionNodesFinished ADD ContentInteractions xml NOT NULL CONSTRAINT DF_PackageSessionNodesFinished_ContentInteractions DEFAULT (('<contentinteractions/>')); ALTER TABLE dbo.PackageSessionNodesFinished DROP CONSTRAINT DF_PackageSessionNodesFinished_ContentInteractions Now, In PackageSessionNodes there are 234 records, in PackageSessionNodesFinished there are 4256946 records. Really would appreciate some help here as I'm stuck.

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  • How do I drop a foerign key in mssql?

    - by mmattax
    I have created a foreign key (in mssql / tsql) by: alter table company add CountryID varchar(3); alter table company add constraint Company_CountryID_FK foreign key(CountryID) references Country; I then run this query: alter table company drop column CountryID; and I get this error: Msg 5074, Level 16, State 4, Line 2 The object 'Company_CountryID_FK' is dependent on column 'CountryID'. Msg 4922, Level 16, State 9, Line 2 ALTER TABLE DROP COLUMN CountryID failed because one or more objects access this column. I have tried this, yet it does not seem to work: alter table company drop foreign key Company_CountryID_FK; alter table company drop column CountryID; What do I need to do to drop the CountryID column? Thanks.

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  • Advanced TSQL Tuning: Why Internals Knowledge Matters

    - by Paul White
    There is much more to query tuning than reducing logical reads and adding covering nonclustered indexes.  Query tuning is not complete as soon as the query returns results quickly in the development or test environments.  In production, your query will compete for memory, CPU, locks, I/O and other resources on the server.  Today’s entry looks at some tuning considerations that are often overlooked, and shows how deep internals knowledge can help you write better TSQL. As always, we’ll need some example data.  In fact, we are going to use three tables today, each of which is structured like this: Each table has 50,000 rows made up of an INTEGER id column and a padding column containing 3,999 characters in every row.  The only difference between the three tables is in the type of the padding column: the first table uses CHAR(3999), the second uses VARCHAR(MAX), and the third uses the deprecated TEXT type.  A script to create a database with the three tables and load the sample data follows: USE master; GO IF DB_ID('SortTest') IS NOT NULL DROP DATABASE SortTest; GO CREATE DATABASE SortTest COLLATE LATIN1_GENERAL_BIN; GO ALTER DATABASE SortTest MODIFY FILE ( NAME = 'SortTest', SIZE = 3GB, MAXSIZE = 3GB ); GO ALTER DATABASE SortTest MODIFY FILE ( NAME = 'SortTest_log', SIZE = 256MB, MAXSIZE = 1GB, FILEGROWTH = 128MB ); GO ALTER DATABASE SortTest SET ALLOW_SNAPSHOT_ISOLATION OFF ; ALTER DATABASE SortTest SET AUTO_CLOSE OFF ; ALTER DATABASE SortTest SET AUTO_CREATE_STATISTICS ON ; ALTER DATABASE SortTest SET AUTO_SHRINK OFF ; ALTER DATABASE SortTest SET AUTO_UPDATE_STATISTICS ON ; ALTER DATABASE SortTest SET AUTO_UPDATE_STATISTICS_ASYNC ON ; ALTER DATABASE SortTest SET PARAMETERIZATION SIMPLE ; ALTER DATABASE SortTest SET READ_COMMITTED_SNAPSHOT OFF ; ALTER DATABASE SortTest SET MULTI_USER ; ALTER DATABASE SortTest SET RECOVERY SIMPLE ; USE SortTest; GO CREATE TABLE dbo.TestCHAR ( id INTEGER IDENTITY (1,1) NOT NULL, padding CHAR(3999) NOT NULL,   CONSTRAINT [PK dbo.TestCHAR (id)] PRIMARY KEY CLUSTERED (id), ) ; CREATE TABLE dbo.TestMAX ( id INTEGER IDENTITY (1,1) NOT NULL, padding VARCHAR(MAX) NOT NULL,   CONSTRAINT [PK dbo.TestMAX (id)] PRIMARY KEY CLUSTERED (id), ) ; CREATE TABLE dbo.TestTEXT ( id INTEGER IDENTITY (1,1) NOT NULL, padding TEXT NOT NULL,   CONSTRAINT [PK dbo.TestTEXT (id)] PRIMARY KEY CLUSTERED (id), ) ; -- ============= -- Load TestCHAR (about 3s) -- ============= INSERT INTO dbo.TestCHAR WITH (TABLOCKX) ( padding ) SELECT padding = REPLICATE(CHAR(65 + (Data.n % 26)), 3999) FROM ( SELECT TOP (50000) n = ROW_NUMBER() OVER (ORDER BY (SELECT 0)) - 1 FROM master.sys.columns C1, master.sys.columns C2, master.sys.columns C3 ORDER BY n ASC ) AS Data ORDER BY Data.n ASC ; -- ============ -- Load TestMAX (about 3s) -- ============ INSERT INTO dbo.TestMAX WITH (TABLOCKX) ( padding ) SELECT CONVERT(VARCHAR(MAX), padding) FROM dbo.TestCHAR ORDER BY id ; -- ============= -- Load TestTEXT (about 5s) -- ============= INSERT INTO dbo.TestTEXT WITH (TABLOCKX) ( padding ) SELECT CONVERT(TEXT, padding) FROM dbo.TestCHAR ORDER BY id ; -- ========== -- Space used -- ========== -- EXECUTE sys.sp_spaceused @objname = 'dbo.TestCHAR'; EXECUTE sys.sp_spaceused @objname = 'dbo.TestMAX'; EXECUTE sys.sp_spaceused @objname = 'dbo.TestTEXT'; ; CHECKPOINT ; That takes around 15 seconds to run, and shows the space allocated to each table in its output: To illustrate the points I want to make today, the example task we are going to set ourselves is to return a random set of 150 rows from each table.  The basic shape of the test query is the same for each of the three test tables: SELECT TOP (150) T.id, T.padding FROM dbo.Test AS T ORDER BY NEWID() OPTION (MAXDOP 1) ; Test 1 – CHAR(3999) Running the template query shown above using the TestCHAR table as the target, we find that the query takes around 5 seconds to return its results.  This seems slow, considering that the table only has 50,000 rows.  Working on the assumption that generating a GUID for each row is a CPU-intensive operation, we might try enabling parallelism to see if that speeds up the response time.  Running the query again (but without the MAXDOP 1 hint) on a machine with eight logical processors, the query now takes 10 seconds to execute – twice as long as when run serially. Rather than attempting further guesses at the cause of the slowness, let’s go back to serial execution and add some monitoring.  The script below monitors STATISTICS IO output and the amount of tempdb used by the test query.  We will also run a Profiler trace to capture any warnings generated during query execution. DECLARE @read BIGINT, @write BIGINT ; SELECT @read = SUM(num_of_bytes_read), @write = SUM(num_of_bytes_written) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; SET STATISTICS IO ON ; SELECT TOP (150) TC.id, TC.padding FROM dbo.TestCHAR AS TC ORDER BY NEWID() OPTION (MAXDOP 1) ; SET STATISTICS IO OFF ; SELECT tempdb_read_MB = (SUM(num_of_bytes_read) - @read) / 1024. / 1024., tempdb_write_MB = (SUM(num_of_bytes_written) - @write) / 1024. / 1024., internal_use_MB = ( SELECT internal_objects_alloc_page_count / 128.0 FROM sys.dm_db_task_space_usage WHERE session_id = @@SPID ) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; Let’s take a closer look at the statistics and query plan generated from this: Following the flow of the data from right to left, we see the expected 50,000 rows emerging from the Clustered Index Scan, with a total estimated size of around 191MB.  The Compute Scalar adds a column containing a random GUID (generated from the NEWID() function call) for each row.  With this extra column in place, the size of the data arriving at the Sort operator is estimated to be 192MB. Sort is a blocking operator – it has to examine all of the rows on its input before it can produce its first row of output (the last row received might sort first).  This characteristic means that Sort requires a memory grant – memory allocated for the query’s use by SQL Server just before execution starts.  In this case, the Sort is the only memory-consuming operator in the plan, so it has access to the full 243MB (248,696KB) of memory reserved by SQL Server for this query execution. Notice that the memory grant is significantly larger than the expected size of the data to be sorted.  SQL Server uses a number of techniques to speed up sorting, some of which sacrifice size for comparison speed.  Sorts typically require a very large number of comparisons, so this is usually a very effective optimization.  One of the drawbacks is that it is not possible to exactly predict the sort space needed, as it depends on the data itself.  SQL Server takes an educated guess based on data types, sizes, and the number of rows expected, but the algorithm is not perfect. In spite of the large memory grant, the Profiler trace shows a Sort Warning event (indicating that the sort ran out of memory), and the tempdb usage monitor shows that 195MB of tempdb space was used – all of that for system use.  The 195MB represents physical write activity on tempdb, because SQL Server strictly enforces memory grants – a query cannot ‘cheat’ and effectively gain extra memory by spilling to tempdb pages that reside in memory.  Anyway, the key point here is that it takes a while to write 195MB to disk, and this is the main reason that the query takes 5 seconds overall. If you are wondering why using parallelism made the problem worse, consider that eight threads of execution result in eight concurrent partial sorts, each receiving one eighth of the memory grant.  The eight sorts all spilled to tempdb, resulting in inefficiencies as the spilled sorts competed for disk resources.  More importantly, there are specific problems at the point where the eight partial results are combined, but I’ll cover that in a future post. CHAR(3999) Performance Summary: 5 seconds elapsed time 243MB memory grant 195MB tempdb usage 192MB estimated sort set 25,043 logical reads Sort Warning Test 2 – VARCHAR(MAX) We’ll now run exactly the same test (with the additional monitoring) on the table using a VARCHAR(MAX) padding column: DECLARE @read BIGINT, @write BIGINT ; SELECT @read = SUM(num_of_bytes_read), @write = SUM(num_of_bytes_written) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; SET STATISTICS IO ON ; SELECT TOP (150) TM.id, TM.padding FROM dbo.TestMAX AS TM ORDER BY NEWID() OPTION (MAXDOP 1) ; SET STATISTICS IO OFF ; SELECT tempdb_read_MB = (SUM(num_of_bytes_read) - @read) / 1024. / 1024., tempdb_write_MB = (SUM(num_of_bytes_written) - @write) / 1024. / 1024., internal_use_MB = ( SELECT internal_objects_alloc_page_count / 128.0 FROM sys.dm_db_task_space_usage WHERE session_id = @@SPID ) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; This time the query takes around 8 seconds to complete (3 seconds longer than Test 1).  Notice that the estimated row and data sizes are very slightly larger, and the overall memory grant has also increased very slightly to 245MB.  The most marked difference is in the amount of tempdb space used – this query wrote almost 391MB of sort run data to the physical tempdb file.  Don’t draw any general conclusions about VARCHAR(MAX) versus CHAR from this – I chose the length of the data specifically to expose this edge case.  In most cases, VARCHAR(MAX) performs very similarly to CHAR – I just wanted to make test 2 a bit more exciting. MAX Performance Summary: 8 seconds elapsed time 245MB memory grant 391MB tempdb usage 193MB estimated sort set 25,043 logical reads Sort warning Test 3 – TEXT The same test again, but using the deprecated TEXT data type for the padding column: DECLARE @read BIGINT, @write BIGINT ; SELECT @read = SUM(num_of_bytes_read), @write = SUM(num_of_bytes_written) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; SET STATISTICS IO ON ; SELECT TOP (150) TT.id, TT.padding FROM dbo.TestTEXT AS TT ORDER BY NEWID() OPTION (MAXDOP 1, RECOMPILE) ; SET STATISTICS IO OFF ; SELECT tempdb_read_MB = (SUM(num_of_bytes_read) - @read) / 1024. / 1024., tempdb_write_MB = (SUM(num_of_bytes_written) - @write) / 1024. / 1024., internal_use_MB = ( SELECT internal_objects_alloc_page_count / 128.0 FROM sys.dm_db_task_space_usage WHERE session_id = @@SPID ) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; This time the query runs in 500ms.  If you look at the metrics we have been checking so far, it’s not hard to understand why: TEXT Performance Summary: 0.5 seconds elapsed time 9MB memory grant 5MB tempdb usage 5MB estimated sort set 207 logical reads 596 LOB logical reads Sort warning SQL Server’s memory grant algorithm still underestimates the memory needed to perform the sorting operation, but the size of the data to sort is so much smaller (5MB versus 193MB previously) that the spilled sort doesn’t matter very much.  Why is the data size so much smaller?  The query still produces the correct results – including the large amount of data held in the padding column – so what magic is being performed here? TEXT versus MAX Storage The answer lies in how columns of the TEXT data type are stored.  By default, TEXT data is stored off-row in separate LOB pages – which explains why this is the first query we have seen that records LOB logical reads in its STATISTICS IO output.  You may recall from my last post that LOB data leaves an in-row pointer to the separate storage structure holding the LOB data. SQL Server can see that the full LOB value is not required by the query plan until results are returned, so instead of passing the full LOB value down the plan from the Clustered Index Scan, it passes the small in-row structure instead.  SQL Server estimates that each row coming from the scan will be 79 bytes long – 11 bytes for row overhead, 4 bytes for the integer id column, and 64 bytes for the LOB pointer (in fact the pointer is rather smaller – usually 16 bytes – but the details of that don’t really matter right now). OK, so this query is much more efficient because it is sorting a very much smaller data set – SQL Server delays retrieving the LOB data itself until after the Sort starts producing its 150 rows.  The question that normally arises at this point is: Why doesn’t SQL Server use the same trick when the padding column is defined as VARCHAR(MAX)? The answer is connected with the fact that if the actual size of the VARCHAR(MAX) data is 8000 bytes or less, it is usually stored in-row in exactly the same way as for a VARCHAR(8000) column – MAX data only moves off-row into LOB storage when it exceeds 8000 bytes.  The default behaviour of the TEXT type is to be stored off-row by default, unless the ‘text in row’ table option is set suitably and there is room on the page.  There is an analogous (but opposite) setting to control the storage of MAX data – the ‘large value types out of row’ table option.  By enabling this option for a table, MAX data will be stored off-row (in a LOB structure) instead of in-row.  SQL Server Books Online has good coverage of both options in the topic In Row Data. The MAXOOR Table The essential difference, then, is that MAX defaults to in-row storage, and TEXT defaults to off-row (LOB) storage.  You might be thinking that we could get the same benefits seen for the TEXT data type by storing the VARCHAR(MAX) values off row – so let’s look at that option now.  This script creates a fourth table, with the VARCHAR(MAX) data stored off-row in LOB pages: CREATE TABLE dbo.TestMAXOOR ( id INTEGER IDENTITY (1,1) NOT NULL, padding VARCHAR(MAX) NOT NULL,   CONSTRAINT [PK dbo.TestMAXOOR (id)] PRIMARY KEY CLUSTERED (id), ) ; EXECUTE sys.sp_tableoption @TableNamePattern = N'dbo.TestMAXOOR', @OptionName = 'large value types out of row', @OptionValue = 'true' ; SELECT large_value_types_out_of_row FROM sys.tables WHERE [schema_id] = SCHEMA_ID(N'dbo') AND name = N'TestMAXOOR' ; INSERT INTO dbo.TestMAXOOR WITH (TABLOCKX) ( padding ) SELECT SPACE(0) FROM dbo.TestCHAR ORDER BY id ; UPDATE TM WITH (TABLOCK) SET padding.WRITE (TC.padding, NULL, NULL) FROM dbo.TestMAXOOR AS TM JOIN dbo.TestCHAR AS TC ON TC.id = TM.id ; EXECUTE sys.sp_spaceused @objname = 'dbo.TestMAXOOR' ; CHECKPOINT ; Test 4 – MAXOOR We can now re-run our test on the MAXOOR (MAX out of row) table: DECLARE @read BIGINT, @write BIGINT ; SELECT @read = SUM(num_of_bytes_read), @write = SUM(num_of_bytes_written) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; SET STATISTICS IO ON ; SELECT TOP (150) MO.id, MO.padding FROM dbo.TestMAXOOR AS MO ORDER BY NEWID() OPTION (MAXDOP 1, RECOMPILE) ; SET STATISTICS IO OFF ; SELECT tempdb_read_MB = (SUM(num_of_bytes_read) - @read) / 1024. / 1024., tempdb_write_MB = (SUM(num_of_bytes_written) - @write) / 1024. / 1024., internal_use_MB = ( SELECT internal_objects_alloc_page_count / 128.0 FROM sys.dm_db_task_space_usage WHERE session_id = @@SPID ) FROM tempdb.sys.database_files AS DBF JOIN sys.dm_io_virtual_file_stats(2, NULL) AS FS ON FS.file_id = DBF.file_id WHERE DBF.type_desc = 'ROWS' ; TEXT Performance Summary: 0.3 seconds elapsed time 245MB memory grant 0MB tempdb usage 193MB estimated sort set 207 logical reads 446 LOB logical reads No sort warning The query runs very quickly – slightly faster than Test 3, and without spilling the sort to tempdb (there is no sort warning in the trace, and the monitoring query shows zero tempdb usage by this query).  SQL Server is passing the in-row pointer structure down the plan and only looking up the LOB value on the output side of the sort. The Hidden Problem There is still a huge problem with this query though – it requires a 245MB memory grant.  No wonder the sort doesn’t spill to tempdb now – 245MB is about 20 times more memory than this query actually requires to sort 50,000 records containing LOB data pointers.  Notice that the estimated row and data sizes in the plan are the same as in test 2 (where the MAX data was stored in-row). The optimizer assumes that MAX data is stored in-row, regardless of the sp_tableoption setting ‘large value types out of row’.  Why?  Because this option is dynamic – changing it does not immediately force all MAX data in the table in-row or off-row, only when data is added or actually changed.  SQL Server does not keep statistics to show how much MAX or TEXT data is currently in-row, and how much is stored in LOB pages.  This is an annoying limitation, and one which I hope will be addressed in a future version of the product. So why should we worry about this?  Excessive memory grants reduce concurrency and may result in queries waiting on the RESOURCE_SEMAPHORE wait type while they wait for memory they do not need.  245MB is an awful lot of memory, especially on 32-bit versions where memory grants cannot use AWE-mapped memory.  Even on a 64-bit server with plenty of memory, do you really want a single query to consume 0.25GB of memory unnecessarily?  That’s 32,000 8KB pages that might be put to much better use. The Solution The answer is not to use the TEXT data type for the padding column.  That solution happens to have better performance characteristics for this specific query, but it still results in a spilled sort, and it is hard to recommend the use of a data type which is scheduled for removal.  I hope it is clear to you that the fundamental problem here is that SQL Server sorts the whole set arriving at a Sort operator.  Clearly, it is not efficient to sort the whole table in memory just to return 150 rows in a random order. The TEXT example was more efficient because it dramatically reduced the size of the set that needed to be sorted.  We can do the same thing by selecting 150 unique keys from the table at random (sorting by NEWID() for example) and only then retrieving the large padding column values for just the 150 rows we need.  The following script implements that idea for all four tables: SET STATISTICS IO ON ; WITH TestTable AS ( SELECT * FROM dbo.TestCHAR ), TopKeys AS ( SELECT TOP (150) id FROM TestTable ORDER BY NEWID() ) SELECT T1.id, T1.padding FROM TestTable AS T1 WHERE T1.id = ANY (SELECT id FROM TopKeys) OPTION (MAXDOP 1) ; WITH TestTable AS ( SELECT * FROM dbo.TestMAX ), TopKeys AS ( SELECT TOP (150) id FROM TestTable ORDER BY NEWID() ) SELECT T1.id, T1.padding FROM TestTable AS T1 WHERE T1.id IN (SELECT id FROM TopKeys) OPTION (MAXDOP 1) ; WITH TestTable AS ( SELECT * FROM dbo.TestTEXT ), TopKeys AS ( SELECT TOP (150) id FROM TestTable ORDER BY NEWID() ) SELECT T1.id, T1.padding FROM TestTable AS T1 WHERE T1.id IN (SELECT id FROM TopKeys) OPTION (MAXDOP 1) ; WITH TestTable AS ( SELECT * FROM dbo.TestMAXOOR ), TopKeys AS ( SELECT TOP (150) id FROM TestTable ORDER BY NEWID() ) SELECT T1.id, T1.padding FROM TestTable AS T1 WHERE T1.id IN (SELECT id FROM TopKeys) OPTION (MAXDOP 1) ; SET STATISTICS IO OFF ; All four queries now return results in much less than a second, with memory grants between 6 and 12MB, and without spilling to tempdb.  The small remaining inefficiency is in reading the id column values from the clustered primary key index.  As a clustered index, it contains all the in-row data at its leaf.  The CHAR and VARCHAR(MAX) tables store the padding column in-row, so id values are separated by a 3999-character column, plus row overhead.  The TEXT and MAXOOR tables store the padding values off-row, so id values in the clustered index leaf are separated by the much-smaller off-row pointer structure.  This difference is reflected in the number of logical page reads performed by the four queries: Table 'TestCHAR' logical reads 25511 lob logical reads 000 Table 'TestMAX'. logical reads 25511 lob logical reads 000 Table 'TestTEXT' logical reads 00412 lob logical reads 597 Table 'TestMAXOOR' logical reads 00413 lob logical reads 446 We can increase the density of the id values by creating a separate nonclustered index on the id column only.  This is the same key as the clustered index, of course, but the nonclustered index will not include the rest of the in-row column data. CREATE UNIQUE NONCLUSTERED INDEX uq1 ON dbo.TestCHAR (id); CREATE UNIQUE NONCLUSTERED INDEX uq1 ON dbo.TestMAX (id); CREATE UNIQUE NONCLUSTERED INDEX uq1 ON dbo.TestTEXT (id); CREATE UNIQUE NONCLUSTERED INDEX uq1 ON dbo.TestMAXOOR (id); The four queries can now use the very dense nonclustered index to quickly scan the id values, sort them by NEWID(), select the 150 ids we want, and then look up the padding data.  The logical reads with the new indexes in place are: Table 'TestCHAR' logical reads 835 lob logical reads 0 Table 'TestMAX' logical reads 835 lob logical reads 0 Table 'TestTEXT' logical reads 686 lob logical reads 597 Table 'TestMAXOOR' logical reads 686 lob logical reads 448 With the new index, all four queries use the same query plan (click to enlarge): Performance Summary: 0.3 seconds elapsed time 6MB memory grant 0MB tempdb usage 1MB sort set 835 logical reads (CHAR, MAX) 686 logical reads (TEXT, MAXOOR) 597 LOB logical reads (TEXT) 448 LOB logical reads (MAXOOR) No sort warning I’ll leave it as an exercise for the reader to work out why trying to eliminate the Key Lookup by adding the padding column to the new nonclustered indexes would be a daft idea Conclusion This post is not about tuning queries that access columns containing big strings.  It isn’t about the internal differences between TEXT and MAX data types either.  It isn’t even about the cool use of UPDATE .WRITE used in the MAXOOR table load.  No, this post is about something else: Many developers might not have tuned our starting example query at all – 5 seconds isn’t that bad, and the original query plan looks reasonable at first glance.  Perhaps the NEWID() function would have been blamed for ‘just being slow’ – who knows.  5 seconds isn’t awful – unless your users expect sub-second responses – but using 250MB of memory and writing 200MB to tempdb certainly is!  If ten sessions ran that query at the same time in production that’s 2.5GB of memory usage and 2GB hitting tempdb.  Of course, not all queries can be rewritten to avoid large memory grants and sort spills using the key-lookup technique in this post, but that’s not the point either. The point of this post is that a basic understanding of execution plans is not enough.  Tuning for logical reads and adding covering indexes is not enough.  If you want to produce high-quality, scalable TSQL that won’t get you paged as soon as it hits production, you need a deep understanding of execution plans, and as much accurate, deep knowledge about SQL Server as you can lay your hands on.  The advanced database developer has a wide range of tools to use in writing queries that perform well in a range of circumstances. By the way, the examples in this post were written for SQL Server 2008.  They will run on 2005 and demonstrate the same principles, but you won’t get the same figures I did because 2005 had a rather nasty bug in the Top N Sort operator.  Fair warning: if you do decide to run the scripts on a 2005 instance (particularly the parallel query) do it before you head out for lunch… This post is dedicated to the people of Christchurch, New Zealand. © 2011 Paul White email: @[email protected] twitter: @SQL_Kiwi

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  • SQL SERVER – Last Two Days to Get FREE Book – Joes 2 Pros Certification 70-433

    - by pinaldave
    Earlier this week we announced that we will be giving away FREE SQL Wait Stats book to everybody who will get SQL Server Joes 2 Pros Combo Kit. We had a fantastic response to the contest. We got an overwhelming response to the offer. We knew there would be a great response but we want to honestly say thank you to all of you for making it happen. Rick and I want to make sure that we express our special thanks to all of you who are reading our books. The offer is still on and there are two more days to avail this offer. We want to make sure that everybody who buys our most selling combo kits, we will send our other most popular SQL Wait Stats book. Please read all the details of the offer here. The books are great resources for anyone who wants to learn SQL Server from fundamentals and eventually go on the certification path of 70-433. Exam 70-433 contains following important subject and the book covers the subject of fundamental. If you are taking the exam or not taking the exam – this book is for every SQL Developer to learn the subject from fundamentals.  Create and alter tables. Create and alter views. Create and alter indexes. Create and modify constraints. Implement data types. Implement partitioning solutions. Create and alter stored procedures. Create and alter user-defined functions (UDFs). Create and alter DML triggers. Create and alter DDL triggers. Create and deploy CLR-based objects. Implement error handling. Manage transactions. Query data by using SELECT statements. Modify data by using INSERT, UPDATE, and DELETE statements. Return data by using the OUTPUT clause. Modify data by using MERGE statements. Implement aggregate queries. Combine datasets. INTERSECT, EXCEPT Implement subqueries. Implement CTE (common table expression) queries. Apply ranking functions. Control execution plans. Manage international considerations. Integrate Database Mail. Implement full-text search. Implement scripts by using Windows PowerShell and SQL Server Management Objects (SMOs). Implement Service Broker solutions. Track data changes. Data capture Retrieve relational data as XML. Transform XML data into relational data. Manage XML data. Capture execution plans. Collect output from the Database Engine Tuning Advisor. Collect information from system metadata. Availability of Book USA - Amazon | India - Flipkart | Indiaplaza Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Joes 2 Pros, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • Need a Quick Sure Method to Produce a Formatted Explain Plan? This will help!

    - by user702295
    Please use the following on the production machine to get formatted explain plan and sql trace using the SLOW sql (e.g. 'T_COMB_LIST.COMB_ID = 216') or any other value that takes longer: -- Open new session is SQL*Plus */ -- Make sure you are using updated PLAN_TABLE -- This can be done by dropping it and recreate it by running: -- SQL> @?/rdbms/admin/utlxplan.sql) set lines 1000 set pages 1000 spool xplan_1.txt EXPLAIN PLAN FOR <<<<Replace this line with exactly the same query you used above. Force hard parse by modifying the case of a character>>>> @?/rdbms/admin/utlxplp spool off EXIT --Open a second session is SQL*Plus ALTER SESSION SET max_dump_file_size = unlimited; ALTER SESSION SET tracefile_identifier = '10046'; ALTER SESSION SET statistics_level = ALL; ALTER SESSION SET events '10046 trace name context forever, level 12'; <<<<Replace this line with exactly the same query you used above. Force hard parse by modifying the case of a character>>>> select 'verify cursor closed' from dual; ALTER SYSTEM SET EVENTS '10046 trace name context off'; EXIT Make sure spooled file is formatted properly and that the 10046 trace has relevant explain plan in it.  Please Upload both files (10046 trace is generated in udump). Need instructions to find udump?   sqlplus "/ as sysdba" show parameters dump_dest This will show you bdump, cdump and udump locations.

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  • ?Oracle Database 12c????ASM Scrubbing Disk Groups

    - by Liu Maclean(???)
    ?12.1?Oracle ASM??????????????????? ??Scrubbing Disk Groups, Disk Scrubbing???????????,?????Normal ??High Redundancy?disk group?????? Scrubbing ?????????????????Disk Scrubbing???disk group rebalancing???????I/O?????Disk Scrubbing??????I/O????? ?????????Scrubbing????,?????,????????????,?????ALTER DISKGROUP?????????: SQL> ALTER DISKGROUP data SCRUB POWER LOW; SQL> ALTER DISKGROUP data SCRUB FILE '+DATA/ORCL/ASKMACLEAN/example.266.806582193' REPAIR POWER HIGH FORCE; SQL> ALTER DISKGROUP data SCRUB DISK DATA_0005 REPAIR POWER HIGH FORCE; ?????SCRUB ?: ??REPAIR??????????,?????REPAIR,?SCRUB???????????????? ??POWER?????AUTO LOW HIGH ??MAX? ?POWER???,???AUTO????? ??WAIT ???????scrubbing ?????????WAIT???,?scrubbing??????scrubbing queue ??,??????? ?FORCE?????,?????I/O????????????????scrubbing ,????????

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  • Render custom form / alter existing rendering template at runtime.

    - by Janis Veinbergs
    How do I create reusable custom new item form + preferrably, i don't want to tie this form to content type? I want to force render one hidden field (it could be render on the page, but make invisible or render on the page and display) and set field value programmatically (that's why it has to be rendered - to set it's value). Google has tons of information on how to create custom list form with sharepoint designer, but in my case, i don't want sharepoint designer for the advantages you see below. What i'm trying to achieve I want to be able to have a custom newform to create item (i don't want it to be as default). To open this newForm i would use CustomAction in item's ECB menu. In this form, i want to force render one hidden field and set it's value programmatically. I want to open this form from CustomAction ECB (item's context menu), so i don't want to set this as a default New form template for content type. <XmlDocument NamespaceURI="http://schemas.microsoft.com/sharepoint/v3/contenttype/forms"> <FormTemplates xmlns="http://schemas.microsoft.com/sharepoint/v3/contenttype/forms"> <New>ListForm</New> </FormTemplates> </XmlDocument> Idea #1 I could create custom RenderingTemplate and set Content type's new form template to my newly created template. For example, OOTB ListForm rendering template: <SharePoint:RenderingTemplate ID="ListForm" runat="server"> <Template> <SPAN id='part1'> <SharePoint:InformationBar runat="server"/> <wssuc:ToolBar CssClass="ms-formtoolbar" id="toolBarTbltop" RightButtonSeparator="&nbsp;" runat="server"> <Template_RightButtons> <SharePoint:NextPageButton runat="server"/> <SharePoint:SaveButton runat="server"/> <SharePoint:GoBackButton runat="server"/> </Template_RightButtons> </wssuc:ToolBar> <SharePoint:FormToolBar runat="server"/> <TABLE class="ms-formtable" style="margin-top: 8px;" border=0 cellpadding=0 cellspacing=0 width=100%> <SharePoint:ChangeContentType runat="server"/> <SharePoint:FolderFormFields runat="server"/> <SharePoint:ListFieldIterator runat="server" /> <SharePoint:ApprovalStatus runat="server"/> <SharePoint:FormComponent TemplateName="AttachmentRows" runat="server"/> </TABLE> <table cellpadding=0 cellspacing=0 width=100%><tr><td class="ms-formline"><IMG SRC="/_layouts/images/blank.gif" width=1 height=1 alt=""></td></tr></table> <TABLE cellpadding=0 cellspacing=0 width=100% style="padding-top: 7px"><tr><td width=100%> <SharePoint:ItemHiddenVersion runat="server"/> <SharePoint:ParentInformationField runat="server"/> <SharePoint:InitContentType runat="server"/> <wssuc:ToolBar CssClass="ms-formtoolbar" id="toolBarTbl" RightButtonSeparator="&nbsp;" runat="server"> <Template_Buttons> <SharePoint:CreatedModifiedInfo runat="server"/> </Template_Buttons> <Template_RightButtons> <SharePoint:SaveButton runat="server"/> <SharePoint:GoBackButton runat="server"/> </Template_RightButtons> </wssuc:ToolBar> </td></tr></TABLE> </SPAN> <SharePoint:AttachmentUpload runat="server"/> </Template> </SharePoint:RenderingTemplate> I only need such a minor change: <SharePoint:RenderingTemplate ID="NewRelatedListItemTemplate" runat="server"> ... <SharePoint:ListFieldIterator TemplateName="ListItemFormFieldsWithRelatedItems" runat="server" /> .. </SharePoint:RenderingTemplate> <SharePoint:RenderingTemplate ID="ListItemFormFieldsWithRelatedItems" runat="server"> <Template> <Balticovo:ListFieldIteratorExtended IncludeFields="RelatedItems" runat="server"/> </Template> </SharePoint:RenderingTemplate> Advantages over manual (SPD) custom forms In this way form is not "constant/static". If new list fields are added to list or content type afterwards, my custom form will render them (the ListFieldIterator will do it). Idea #2 Could it be that i modify existing RenderingTemplate at runtime? I would take "new forms" template (Named, for example, ListForm or it could be other than default ListForm) with SPControlTemplateManager.GetTemplateByName("ListForm") Find ListIterator control and add property TemplateName="ListItemFormFieldsWithRelatedItems" Render this template and return it? In short, i would like to create RenderingTemplate programmatically, on-the-fly and then use this template to render list's new form. Advantages I get the advantage of Idea 1 + This way i would get a bonus even if Template changes (from ListForm to CompanyCustomListForm) and my custom form won't loose my implemented functionality if i choose to change content type's rendering template later on (i can create other features not trying to rembeer to reimplement this particular stuff or other 3rd party features won't override my functionality if they use custom forms - loose coupling is it?). Now, is this (Idea #2) possible...?

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  • Mysql query help - Alter this mysql query to get these results?

    - by sandeepan-nath
    Please execute the following queries first to set up so that you can help me:- CREATE TABLE IF NOT EXISTS `Tutor_Details` ( `id_tutor` int(10) NOT NULL auto_increment, `firstname` varchar(100) NOT NULL default '', `surname` varchar(155) NOT NULL default '', PRIMARY KEY (`id_tutor`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=41 ; INSERT INTO `Tutor_Details` (`id_tutor`,`firstname`, `surname`) VALUES (1, 'Sandeepan', 'Nath'), (2, 'Bob', 'Cratchit'); CREATE TABLE IF NOT EXISTS `Classes` ( `id_class` int(10) unsigned NOT NULL auto_increment, `id_tutor` int(10) unsigned NOT NULL default '0', `class_name` varchar(255) default NULL, PRIMARY KEY (`id_class`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=229 ; INSERT INTO `Classes` (`id_class`,`class_name`, `id_tutor`) VALUES (1, 'My Class', 1), (2, 'Sandeepan Class', 2); CREATE TABLE IF NOT EXISTS `Tags` ( `id_tag` int(10) unsigned NOT NULL auto_increment, `tag` varchar(255) default NULL, PRIMARY KEY (`id_tag`), UNIQUE KEY `tag` (`tag`), KEY `id_tag` (`id_tag`), KEY `tag_2` (`tag`), KEY `tag_3` (`tag`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=18 ; INSERT INTO `Tags` (`id_tag`, `tag`) VALUES (1, 'Bob'), (6, 'Class'), (2, 'Cratchit'), (4, 'Nath'), (3, 'Sandeepan'), (5, 'My'); CREATE TABLE IF NOT EXISTS `Tutors_Tag_Relations` ( `id_tag` int(10) unsigned NOT NULL default '0', `id_tutor` int(10) default NULL, KEY `Tutors_Tag_Relations` (`id_tag`), KEY `id_tutor` (`id_tutor`), KEY `id_tag` (`id_tag`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1; INSERT INTO `Tutors_Tag_Relations` (`id_tag`, `id_tutor`) VALUES (3, 1), (4, 1), (1, 2), (2, 2); CREATE TABLE IF NOT EXISTS `Class_Tag_Relations` ( `id_tag` int(10) unsigned NOT NULL default '0', `id_class` int(10) default NULL, `id_tutor` int(10) NOT NULL, KEY `Class_Tag_Relations` (`id_tag`), KEY `id_class` (`id_class`), KEY `id_tag` (`id_tag`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1; INSERT INTO `Class_Tag_Relations` (`id_tag`, `id_class`, `id_tutor`) VALUES (5, 1, 1), (6, 1, 1), (3, 2, 2), (6, 2, 2); In the present system data which I have given , tutor named "Sandeepan Nath" has has created class named "My Class" and tutor named "Bob Cratchit" has created class named "Sandeepan Class". Requirement - To execute a single query with limit on the results to show search results as per AND logic on the search keywords like this:- If "Sandeepan Class" is searched , Tutor Sandeepan Nath's record from Tutor Details table is returned(because "Sandeepan" is the firstname of Sandeepan Nath and Class is present in class name of Sandeepan's class) If "Class" is searched Both the tutors from the Tutor_details table are fetched because Class is present in the name of the class created by both the tutors. Following is what I have so far achieved (PHP Mysql):- <?php $searchTerm1 = "Sandeepan"; $searchTerm2 = "Class"; mysql_select_db("test"); $sql = "SELECT td.* FROM Tutor_Details AS td LEFT JOIN Tutors_Tag_Relations AS ttagrels ON td.id_tutor = ttagrels.id_tutor LEFT JOIN Classes AS wc ON td.id_tutor = wc.id_tutor LEFT JOIN Class_Tag_Relations AS wtagrels ON td.id_tutor = wtagrels.id_tutor LEFT JOIN Tags as t1 on ((t1.id_tag = ttagrels.id_tag) OR (t1.id_tag = wtagrels.id_tag)) LEFT JOIN Tags as t2 on ((t2.id_tag = ttagrels.id_tag) OR (t2.id_tag = wtagrels.id_tag)) where t1.tag LIKE '%".$searchTerm1."%' AND t2.tag LIKE '%".$searchTerm2."%' GROUP BY td.id_tutor LIMIT 10 "; $result = mysql_query($sql); echo $sql; if($result) { while($rec = mysql_fetch_object($result)) $recs[] = $rec; //$rec = mysql_fetch_object($result); echo "<br><br>"; if(is_array($recs)) { foreach($recs as $each) { print_r($each); echo "<br>"; } } } ?> But the results are :- If "Sandeepan Nath" is searched, it does not return any tutor (instead of only Sandeepan's row) If "Sandeepan Class" is searched, it returns Sandeepan's row (instead of Both tutors ) If "Bob Class" is searched, it correctly returns Bob's row If "Bob Cratchit" is searched, it does not return any tutor (instead of only

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  • SimpleRepository auto migrations with indexes

    - by scott
    I am using subsonic simplerepo with migrations in dev and it makes things pretty easy but I keep running into issues with my nvarchar columns that have an index. My users table has an index defined on the username column for obvious reasons but each time I start the project subsonic is doing this: ALTER TABLE [Users] ALTER COLUMN Username nvarchar(50); which causes this: The index 'IX_Username' is dependent on column 'Username'.ALTER TABLE ALTER COLUMN Username failed because one or more objects access this column Is there any way around this issue?

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  • Is it possible to alter a marked field´s field function with Word 2007 VBA?

    - by Richard
    Hi, i want do the following: In Word 2007 place the Cursor on a field (or mark that field) and call a macro wich edit the field function of that field. (add some string). I´m even grateful for some tipps what term to google. I used the macro recorder and got following: WordBasic.FormatField Field:="CITATION Gro05 \p 9 \l 1031" Thats obvious creats a new field but where to go from here? To get the selected field i thought about something like this: If Selection.Type = WdFieldType Then ... I hope someone give me some hints :) Bye Richard

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  • How can I alter anythingSlider so that it disables the next / previous buttons when only 1 <li> in t

    - by madphill
    I have a page with multiple instances of anythingSlider on it and I'm using PHP to dynamically load pages that swap out the content in them. Reference: http://ceedcreative.com/CEED_2.0/ I would like to edit the anythingSlider to disable the previous / next buttons if the UL it's displaying only has one LI within it. In other words, no buttons, just a clean div that's the same heigh and width (no scrolling) if there's only one image.

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  • When to alter a function vs when to just write a new one...?

    - by Andrew Heath
    /is n00b Through the gift of knowledge and expertise encoded here, I am doing my best to avoid n00b mistakes as I learn the basics of programming. I use functions when I (think I) can in PHP, and keep them somewhat sorted in different includes. The n00b problem I'm running into now is situations where perhaps 4/5th of an existing function is relevant to a new need. Maybe there are a slightly different set of inputs, or an additional calculation or two in the series, or output needs a different format/structure... but the core of the function is still applicable. Is there a good rule of thumb regarding when one should bolt-on crap to an original function and when one should (literally) copy & paste most of it into a new function and tweak to fit the situation? On the one hand I feel bad duping code, on the other I feel bad cluttering up an existing function with stuff not always needed...

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