Index Defrag Script Updates – Beta Testers Needed
Filed under: Miscellaneous, Performance & Tuning, SQL 2008, Syndication, T-SQL Scripts
Update: Wow! I’ve received a ton of responses to my request for beta testers. Thank you all! The SQL Community is really amazing. I’ll hopefully have the new version online in just a few days.
Over the last few months, I’ve received many great comments and suggestions regarding my Index Defrag Script v3.0. I’ve just recently had time to implement most of these suggestions, plus some other things that I thought would be useful.
Here’s some of what you can look forward to shortly:
- Probably the single most requested feature, the new version of the script allows you to set a time limit for index defrags.
- There’s now a static table for managing the status of index defrags. This way, when your time limit is reached, you can pick up where you left off the next day, without the need to rescan indexes.
- There’s now an option to prioritize defrags by range scan counts, fragmentation level, or page counts.
- For those using partitioning, there is now an option to exclude the right-most populated partition from defrags (in theory, the one you’re writing to in a sliding-window scenario).
- Options such as page count limits and SORT_IN_TEMPDB are now parameterized.
- I’ve enhanced error logging.
- … and more!
Right now, I’m looking for a few folks who are willing to beta test the script. If you’re interested, please send me an e-mail at michelle at sqlfool dot com with the editions of SQL Server you can test this on (i.e. 2005 Standard, 2008 Enterprise, etc.).
Thank you!
Monitoring Process for Performance Counters
Filed under: Performance & Tuning, Syndication, T-SQL Scripts
Recently I needed to create a process to monitor performance counters over a short period of time. We were going to implement a change and we wanted to compare performance before and after to see if there was any impact.
To do this, I first created a couple of tables. One table is used to actually store the monitored values. The second table is used for configuration; you insert only the counters you want to monitor.
/* Create the table to store our logged perfmon counters */ CREATE TABLE dbo.dba_perfCounterMonitor ( capture_id INT IDENTITY(1,1) Not Null , captureDate SMALLDATETIME Not Null , objectName NVARCHAR(128) Not Null , counterName NVARCHAR(128) Not Null , instanceName NVARCHAR(128) Not Null , VALUE FLOAT(6) Not Null , valueType NVARCHAR(10) Not Null CONSTRAINT PK_dba_perfCounterMonitor PRIMARY KEY CLUSTERED(capture_id) ); /* Create the table that controls which counters we're going to monitor */ CREATE TABLE dbo.dba_perfCounterMonitorConfig ( objectName NVARCHAR(128) Not Null , counterName NVARCHAR(128) Not Null , instanceName NVARCHAR(128) Null );
If you leave the instanceName NULL in the config table, it’ll monitor all instances. Now we’re going to insert some sample performance counters into the config table. The counters you’re interested in can, and likely will, vary.
/* Insert some perfmon counters to be monitored */ INSERT INTO dbo.dba_perfCounterMonitorConfig SELECT 'SQLServer:Buffer Manager', 'Page Life Expectancy', Null UNION All SELECT 'SQLServer:Locks', 'Lock Requests/sec', Null UNION All SELECT 'SQLServer:Locks', 'Lock Waits/sec', Null UNION All SELECT 'SQLServer:Locks', 'Lock Wait Time (ms)', Null UNION All SELECT 'SQLServer:Buffer Manager', 'Page reads/sec', Null UNION All SELECT 'SQLServer:Buffer Manager', 'Page writes/sec', Null UNION All SELECT 'SQLServer:Buffer Manager', 'Buffer cache hit ratio', Null UNION All SELECT 'SQLServer:Databases', 'Transactions/sec', 'AdventureWorks' UNION All SELECT 'SQLServer:General Statistics', 'Processes blocked', Null;
Now let’s create our proc. This proc will run for a specified time period and will *average* the counters over that time. I personally take snapshots every 15 seconds for 4 minutes; I have a scheduled task that runs this every 5 minutes. It’s not perfect, but it gives me a good idea of what’s happening on the server.
CREATE PROCEDURE dbo.dba_perfCounterMonitor_sp /* Declare Parameters */ @samplePeriod INT = 240 /* how long to sample, in seconds */ , @sampleRate CHAR(8) = '00:00:15' /* how frequently to sample, in seconds */ , @displayResults BIT = 0 /* display the results when done */ AS /********************************************************************************* Name: dba_perfCounterMonitor_sp Author: Michelle Ufford, http://sqlfool.com Purpose: Monitors performance counters. Uses the dba_perfCounterMonitorConfig table to manage which perf counters to monitor. @samplePeriod - specifies how long the process will try to monitor performance counters; in seconds. @sampleRate - how long inbetween samples; in seconds. The average values over sample period is then logged to the dba_perfCounterMonitor table. Notes: There are 3 basic types of performance counter calculations: Value/Base: these calculations require 2 counters. The value counter (cntr_type = 537003264) has to be divided by the base counter (cntr_type = 1073939712). Per Second: these counters are store cumulative values; the value must be compared at 2 different times to calculate the difference (cntr_type = 537003264). Point In Time: these counters show what the value of the counter is at the current point-in-time (cntr_type = 65792). No calculation is necessary to derive the value. Called by: DBA Date User Description ---------------------------------------------------------------------------- 2009-09-04 MFU Initial Release ********************************************************************************* Exec dbo.dba_perfCounterMonitor_sp @samplePeriod = 60 , @sampleRate = '00:00:01' , @displayResults = 1; *********************************************************************************/ SET NOCOUNT ON; SET XACT_Abort ON; SET Ansi_Padding ON; SET Ansi_Warnings ON; SET ArithAbort ON; SET Concat_Null_Yields_Null ON; SET Numeric_RoundAbort OFF; BEGIN /* Declare Variables */ DECLARE @startTime DATETIME , @endTime DATETIME , @iteration INT; SELECT @startTime = GETDATE() , @iteration = 1; DECLARE @samples TABLE ( iteration INT Not Null , objectName NVARCHAR(128) Not Null , counterName NVARCHAR(128) Not Null , instanceName NVARCHAR(128) Not Null , cntr_value FLOAT Not Null , base_value FLOAT Null , cntr_type BIGINT Not Null ); BEGIN Try /* Start a new transaction */ BEGIN TRANSACTION; /* Grab all of our counters */ INSERT INTO @samples SELECT @iteration , RTRIM(dopc.OBJECT_NAME) , RTRIM(dopc.counter_name) , RTRIM(dopc.instance_name) , RTRIM(dopc.cntr_value) , (SELECT cntr_value FROM sys.dm_os_performance_counters AS dopc1 WHERE dopc1.OBJECT_NAME = pcml.objectName And dopc1.counter_name = pcml.counterName + ' base' And dopc1.instance_name = IsNull(pcml.instanceName, dopc.instance_name)) , dopc.cntr_type FROM sys.dm_os_performance_counters AS dopc Join dbo.dba_perfCounterMonitorConfig AS pcml ON dopc.OBJECT_NAME = pcml.objectName And dopc.counter_name = pcml.counterName And dopc.instance_name = IsNull(pcml.instanceName, dopc.instance_name); /* During our sample period, grab our counter values and store the results */ WHILE GETDATE() < DATEADD(SECOND, @samplePeriod, @startTime) BEGIN SET @iteration = @iteration + 1; INSERT INTO @samples SELECT @iteration , RTRIM(dopc.OBJECT_NAME) , RTRIM(dopc.counter_name) , RTRIM(dopc.instance_name) , dopc.cntr_value , (SELECT cntr_value FROM sys.dm_os_performance_counters AS dopc1 WHERE dopc1.OBJECT_NAME = pcml.objectName And dopc1.counter_name = pcml.counterName + ' base' And dopc1.instance_name = IsNull(pcml.instanceName, dopc.instance_name)) , dopc.cntr_type FROM sys.dm_os_performance_counters AS dopc Join dbo.dba_perfCounterMonitorConfig AS pcml ON dopc.OBJECT_NAME = pcml.objectName And dopc.counter_name = pcml.counterName And dopc.instance_name = IsNull(pcml.instanceName, dopc.instance_name); /* Wait for a small delay */ WAITFOR Delay @sampleRate; END; /* Grab our end time for calculations */ SET @endTime = GETDATE(); /* Store the average of our point-in-time counters */ INSERT INTO dbo.dba_perfCounterMonitor ( captureDate , objectName , counterName , instanceName , VALUE , valueType ) SELECT @startTime , objectName , counterName , instanceName , AVG(cntr_value) , 'value' FROM @samples WHERE cntr_type = 65792 GROUP BY objectName , counterName , instanceName; /* Store the average of the value vs the base for cntr_type = 537003264 */ INSERT INTO dbo.dba_perfCounterMonitor ( captureDate , objectName , counterName , instanceName , VALUE , valueType ) SELECT @startTime , objectName , counterName , instanceName , AVG(cntr_value)/AVG(IsNull(base_value, 1)) , 'percent' FROM @samples WHERE cntr_type = 537003264 GROUP BY objectName , counterName , instanceName; /* Compare the first and last values for our cumulative, per-second counters */ INSERT INTO dbo.dba_perfCounterMonitor ( captureDate , objectName , counterName , instanceName , VALUE , valueType ) SELECT @startTime , objectName , counterName , instanceName , (MAX(cntr_value) - MIN(cntr_value)) / DATEDIFF(SECOND, @startTime, @endTime) , 'value' FROM @samples WHERE cntr_type = 272696576 GROUP BY objectName , counterName , instanceName; /* Should we display the results of our most recent execution? */ IF @displayResults = 1 SELECT captureDate , objectName , counterName , instanceName , VALUE , valueType FROM dbo.dba_perfCounterMonitor WITH (NoLock) WHERE captureDate = CAST(@startTime AS SMALLDATETIME) ORDER BY objectName , counterName , instanceName; /* If you have an open transaction, commit it */ IF @@TRANCOUNT > 0 COMMIT TRANSACTION; END Try BEGIN Catch /* Whoops, there was an error... rollback! */ IF @@TRANCOUNT > 0 ROLLBACK TRANSACTION; /* Return an error message and log it */ EXECUTE dbo.dba_logError_sp; END Catch; SET NOCOUNT OFF; RETURN 0; END Go
Like I said, it’s not perfect, but it gets the job done.
Getting an error about dba_logError_sp? Take a look at my error handling proc.
Find Recently Executed Stored Procedures
This past weekend, we had an issue where replication fell far behind on one of our databases. The replicated database is used for all sorts of reporting, so the immediate need was to identify processes that may have been affected by the incomplete data.
Now, there’s hundreds of stored procedures that reference the affected database; the trick is finding out which ones are relevant. To do this, I used the sys.dm_exec_query_stats DMV. This does two things for me. One, it shows me a list of stored procedures in cache, meaning they’ve been executed relatively recently and are probably relevant to the search. Secondly, it shows me the last execution time, which in some cases may have been before the issue, meaning I do not need to worry about re-running those processes.
Here’s the query I used:
SELECT DB_NAME(dest.[dbid]) AS 'databaseName' , OBJECT_NAME(dest.objectid, dest.[dbid]) AS 'procName' , MAX(deqs.last_execution_time) AS 'last_execution' FROM sys.dm_exec_query_stats AS deqs Cross Apply sys.dm_exec_sql_text(deqs.sql_handle) AS dest WHERE dest.[TEXT] Like '%yourTableName%' -- replace And dest.[dbid] IS Not Null -- exclude ad-hocs GROUP BY DB_NAME(dest.[dbid]) , OBJECT_NAME(dest.objectid, dest.[dbid]) ORDER BY databaseName , procName OPTION (MaxDop 1);
This will return results similar to:
databaseName procName last_execution -------------------- ------------------------------ ----------------------- AdventureWorks ufnGetProductListPrice 2009-08-03 09:57:25.390 AdventureWorksDW DimProductCategoryGet_sp 2009-08-03 09:59:05.820 AdventureWorksDW DimProductGet_sp 2009-08-03 09:58:38.370
I want to stress that this is *not* a list of all referencing objects, but rather a list of recently executed stored procedures that are still in memory. This list may not be accurate if your cache has recently been flushed or if you’ve recently rebooted your server.
Index Defrag Script Update
A couple of people pointed out to me that the stats rebuild feature in my defrag script will only complete for one database. Whoopsies! I’ve fixed the bug and updated the script in my previous post, so if you’re using my defrag script, please update it. Thanks to Derick and SuperCoolMoss for letting me know about the bug.
I’ve also received a couple of other requests for feature enhancements. I’m currently swamped at work and outside of work, but as soon as I get time, I will release the latest version. Realistically, it’ll probably be sometime after summer ends.
Thank you to everyone for their comments and suggestions!
Index Defrag Script, v3.0
Filed under: Performance & Tuning, SQL 2008, Syndication, T-SQL Scripts
I’ve just completed the latest version of my index defrag script! Here’s a brief list of the updates:
- Fixed a bug with the LOB logic. In the previous version, after a LOB was encountered, all subsequent indexes would be reorganized.
- Added support for stat rebuilds after the index defrag is complete (@rebuildStats)
- Added an exclusion list table (dba_indexDefragExclusion) to support index scheduling
- Modified logging to show which defrags are “in progress”; added columns to dba_indexDefragLog
- Added support for the defrag of the model and msdb databases
- Added @scanMode as a configurable parameter
So what can this index defrag script do? Well, for starters, you can:
- Schedule it to run with the default settings; it works “right out of the box” with no additional configuration necessary
- Run this one script from a centralized database for all databases on a server
- Run this script for a specific database or table
- Configure custom threshold limits and the point at which a rebuild should be performed (instead of a reorganize)
- Defrag individual partitions
- Log its actions and the duration of the defrag
- Run in “commands only” mode (@executeSQL = 0, @printCommands = 1)
- Customize performance parameters such as @maxDopRestriction and @defragDelay to minimize impact on the server
- Schedule specific indexes to only be defragged on weekends, or every other day
To use this last option, you need to add a record to the dba_indexDefragExclusion table. I think all of the columns are pretty self-explanatory except the [exclusionMask] column. The way this works is each day of the week is assigned a value:
1=Sunday, 2=Monday, 4=Tuesday, 8=Wednesday, 16=Thursday, 32=Friday, 64=Saturday
Take a SUM of the values for the days that you want excluded. So if you want an index to only be defragged on weekends, you would add up Monday through Friday (2+4+8+16+32) and use a value of 62 for the exclusionMask column. For a little more information on how this works, check out my blog post on Bitwise Operations.
Please note: if you don’t insert any records into the dba_indexDefragExclusion table, by default all indexes will be defragged every run-time if they exceed the specified thresholds. This is normal behavior and may be perfectly fine in your environment. However, if the dba_indexDefragExclusion table does not exist, the script will fail.
I try to document each parameter within the code, so check the comments section in the script for a full list of parameters and what they do.
Special thanks to everyone who helped beta test this script!
Without further ado, the script:
/* Drop Table Scripts: Drop Table dbo.dba_indexDefragLog; Drop Table dbo.dba_indexDefragExclusion; */ IF Not Exists(SELECT [OBJECT_ID] FROM sys.tables WHERE [name] In (N'dba_indexDefragLog', 'dba_indexDefragExclusion')) BEGIN CREATE TABLE dbo.dba_indexDefragLog ( indexDefrag_id INT IDENTITY(1,1) Not Null , databaseID INT Not Null , databaseName NVARCHAR(128) Not Null , objectID INT Not Null , objectName NVARCHAR(128) Not Null , indexID INT Not Null , indexName NVARCHAR(128) Not Null , partitionNumber SMALLINT Not Null , fragmentation FLOAT Not Null , page_count INT Not Null , dateTimeStart DATETIME Not Null , dateTimeEnd DATETIME Null , durationSeconds INT Null CONSTRAINT PK_indexDefragLog PRIMARY KEY CLUSTERED (indexDefrag_id) ); PRINT 'dba_indexDefragLog Table Created'; CREATE TABLE dbo.dba_indexDefragExclusion ( databaseID INT Not Null , databaseName NVARCHAR(128) Not Null , objectID INT Not Null , objectName NVARCHAR(128) Not Null , indexID INT Not Null , indexName NVARCHAR(128) Not Null , exclusionMask INT Not Null /* 1=Sunday, 2=Monday, 4=Tuesday, 8=Wednesday, 16=Thursday, 32=Friday, 64=Saturday */ CONSTRAINT PK_indexDefragExclusion PRIMARY KEY CLUSTERED (databaseID, objectID, indexID) ); PRINT 'dba_indexDefragExclusion Table Created'; END ELSE RAISERROR('One or more tables already exist. Please drop or rename before proceeding.', 16, 0); IF OBJECTPROPERTY(OBJECT_ID('dbo.dba_indexDefrag_sp'), N'IsProcedure') = 1 BEGIN DROP PROCEDURE dbo.dba_indexDefrag_sp; PRINT 'Procedure dba_indexDefrag_sp dropped'; END; Go CREATE PROCEDURE dbo.dba_indexDefrag_sp /* Declare Parameters */ @minFragmentation FLOAT = 5.0 /* in percent, will not defrag if fragmentation less than specified */ , @rebuildThreshold FLOAT = 30.0 /* in percent, greater than @rebuildThreshold will result in rebuild instead of reorg */ , @executeSQL BIT = 1 /* 1 = execute; 0 = print command only */ , @DATABASE VARCHAR(128) = Null /* Option to specify a database name; null will return all */ , @tableName VARCHAR(4000) = Null -- databaseName.schema.tableName /* Option to specify a table name; null will return all */ , @scanMode VARCHAR(10) = N'LIMITED' /* Options are LIMITED, SAMPLED, and DETAILED */ , @onlineRebuild BIT = 1 /* 1 = online rebuild; 0 = offline rebuild; only in Enterprise */ , @maxDopRestriction TINYINT = Null /* Option to restrict the number of processors for the operation; only in Enterprise */ , @printCommands BIT = 0 /* 1 = print commands; 0 = do not print commands */ , @printFragmentation BIT = 0 /* 1 = print fragmentation prior to defrag; 0 = do not print */ , @defragDelay CHAR(8) = '00:00:05' /* time to wait between defrag commands */ , @debugMode BIT = 0 /* display some useful comments to help determine if/where issues occur */ , @rebuildStats BIT = 1 /* option to rebuild stats after completed index defrags */ AS /********************************************************************************* Name: dba_indexDefrag_sp Author: Michelle Ufford, http://sqlfool.com Purpose: Defrags all indexes for the current database Notes: CAUTION: TRANSACTION LOG SIZE SHOULD BE MONITORED CLOSELY WHEN DEFRAGMENTING. @minFragmentation defaulted to 10%, will not defrag if fragmentation is less than that @rebuildThreshold defaulted to 30% as recommended by Microsoft in BOL; greater than 30% will result in rebuild instead @executeSQL 1 = execute the SQL generated by this proc; 0 = print command only @database Optional, specify specific database name to defrag; If not specified, all non-system databases will be defragged. @tableName Specify if you only want to defrag indexes for a specific table, format = databaseName.schema.tableName; if not specified, all tables will be defragged. @scanMode Specifies which scan mode to use to determine fragmentation levels. Options are: LIMITED - scans the parent level; quickest mode, recommended for most cases. SAMPLED - samples 1% of all data pages; if less than 10k pages, performs a DETAILED scan. DETAILED - scans all data pages. Use great care with this mode, as it can cause performance issues. @onlineRebuild 1 = online rebuild; 0 = offline rebuild @maxDopRestriction Option to specify a processor limit for index rebuilds @printCommands 1 = print commands to screen; 0 = do not print commands @printFragmentation 1 = print fragmentation to screen; 0 = do not print fragmentation @defragDelay Time to wait between defrag commands; gives the server a little time to catch up @debugMode 1 = display debug comments; helps with troubleshooting 0 = do not display debug comments @rebuildStats Affects only statistics that need to be rebuilt 1 = rebuild stats 0 = do not rebuild stats Called by: SQL Agent Job or DBA Date Initials Version Description ---------------------------------------------------------------------------- 2007-12-18 MFU 1.0 Initial Release 2008-10-17 MFU 1.1 Added @defragDelay, CIX_temp_indexDefragList 2008-11-17 MFU 1.2 Added page_count to log table , added @printFragmentation option 2009-03-17 MFU 2.0 Provided support for centralized execution , consolidated Enterprise & Standard versions , added @debugMode, @maxDopRestriction , modified LOB and partition logic 2009-06-18 MFU 3.0 Fixed bug in LOB logic, added @scanMode option , added support for stat rebuilds (@rebuildStats) , support model and msdb defrag , added columns to the dba_indexDefragLog table , modified logging to show "in progress" defrags , added defrag exclusion list (scheduling) ********************************************************************************* Exec dbo.dba_indexDefrag_sp @executeSQL = 0 , @printCommands = 1 , @debugMode = 1 , @printFragmentation = 1; *********************************************************************************/ SET NOCOUNT ON; SET XACT_Abort ON; SET Ansi_Padding ON; SET Ansi_Warnings ON; SET ArithAbort ON; SET Concat_Null_Yields_Null ON; SET Numeric_RoundAbort OFF; SET Quoted_Identifier ON; BEGIN IF @debugMode = 1 RAISERROR('Undusting the cogs and starting up...', 0, 42) WITH NoWait; /* Declare our variables */ DECLARE @objectID INT , @databaseID INT , @databaseName NVARCHAR(128) , @indexID INT , @partitionCount BIGINT , @schemaName NVARCHAR(128) , @objectName NVARCHAR(128) , @indexName NVARCHAR(128) , @partitionNumber SMALLINT , @fragmentation FLOAT , @pageCount INT , @sqlCommand NVARCHAR(4000) , @rebuildCommand NVARCHAR(200) , @dateTimeStart DATETIME , @dateTimeEnd DATETIME , @containsLOB BIT , @editionCheck BIT , @debugMessage VARCHAR(128) , @updateSQL NVARCHAR(4000) , @partitionSQL NVARCHAR(4000) , @partitionSQL_Param NVARCHAR(1000) , @LOB_SQL NVARCHAR(4000) , @LOB_SQL_Param NVARCHAR(1000) , @rebuildStatsID INT , @rebuildStatsSQL NVARCHAR(1000) , @indexDefrag_id INT; /* Create our temporary tables */ CREATE TABLE #indexDefragList ( databaseID INT , databaseName NVARCHAR(128) , objectID INT , indexID INT , partitionNumber SMALLINT , fragmentation FLOAT , page_count INT , defragStatus BIT , schemaName NVARCHAR(128) Null , objectName NVARCHAR(128) Null , indexName NVARCHAR(128) Null ); CREATE TABLE #databaseList ( databaseID INT , databaseName VARCHAR(128) , scanStatus BIT , statsStatus BIT ); CREATE TABLE #processor ( [INDEX] INT , Name VARCHAR(128) , Internal_Value INT , Character_Value INT ); IF @debugMode = 1 RAISERROR('Beginning validation...', 0, 42) WITH NoWait; /* Just a little validation... */ IF @minFragmentation Not Between 0.00 And 100.0 SET @minFragmentation = 10.0; IF @rebuildThreshold Not Between 0.00 And 100.0 SET @rebuildThreshold = 30.0; IF @defragDelay Not Like '00:[0-5][0-9]:[0-5][0-9]' SET @defragDelay = '00:00:05'; IF @scanMode Not In ('LIMITED', 'SAMPLED', 'DETAILED') SET @scanMode = 'LIMITED'; /* Make sure we're not exceeding the number of processors we have available */ INSERT INTO #processor EXECUTE XP_MSVER 'ProcessorCount'; IF @maxDopRestriction IS Not Null And @maxDopRestriction > (SELECT Internal_Value FROM #processor) SELECT @maxDopRestriction = Internal_Value FROM #processor; /* Check our server version; 1804890536 = Enterprise, 610778273 = Enterprise Evaluation, -2117995310 = Developer */ IF (SELECT SERVERPROPERTY('EditionID')) In (1804890536, 610778273, -2117995310) SET @editionCheck = 1 -- supports online rebuilds ELSE SET @editionCheck = 0; -- does not support online rebuilds IF @debugMode = 1 RAISERROR('Grabbing a list of our databases...', 0, 42) WITH NoWait; /* Retrieve the list of databases to investigate */ INSERT INTO #databaseList SELECT database_id , name , 0 -- not scanned yet for fragmentation , 0 -- statistics not yet updated FROM sys.databases WHERE name = IsNull(@DATABASE, name) And [name] Not In ('master', 'tempdb')-- exclude system databases And [STATE] = 0; -- state must be ONLINE IF @debugMode = 1 RAISERROR('Looping through our list of databases and checking for fragmentation...', 0, 42) WITH NoWait; /* Loop through our list of databases */ WHILE (SELECT COUNT(*) FROM #databaseList WHERE scanStatus = 0) > 0 BEGIN SELECT TOP 1 @databaseID = databaseID FROM #databaseList WHERE scanStatus = 0; SELECT @debugMessage = ' working on ' + DB_NAME(@databaseID) + '...'; IF @debugMode = 1 RAISERROR(@debugMessage, 0, 42) WITH NoWait; /* Determine which indexes to defrag using our user-defined parameters */ INSERT INTO #indexDefragList SELECT database_id AS databaseID , QUOTENAME(DB_NAME(database_id)) AS 'databaseName' , [OBJECT_ID] AS objectID , index_id AS indexID , partition_number AS partitionNumber , avg_fragmentation_in_percent AS fragmentation , page_count , 0 AS 'defragStatus' /* 0 = unprocessed, 1 = processed */ , Null AS 'schemaName' , Null AS 'objectName' , Null AS 'indexName' FROM sys.dm_db_index_physical_stats (@databaseID, OBJECT_ID(@tableName), Null , Null, @scanMode) WHERE avg_fragmentation_in_percent >= @minFragmentation And index_id > 0 -- ignore heaps And page_count > 8 -- ignore objects with less than 1 extent And index_level = 0 -- leaf-level nodes only, supports @scanMode OPTION (MaxDop 2); /* Keep track of which databases have already been scanned */ UPDATE #databaseList SET scanStatus = 1 WHERE databaseID = @databaseID; END CREATE CLUSTERED INDEX CIX_temp_indexDefragList ON #indexDefragList(databaseID, objectID, indexID, partitionNumber); /* Delete any indexes from our to-do that are also in our exclusion list for today */ DELETE idl FROM #indexDefragList AS idl Join dbo.dba_indexDefragExclusion AS ide ON idl.databaseID = ide.databaseID And idl.objectID = ide.objectID And idl.indexID = ide.indexID WHERE exclusionMask & POWER(2, DATEPART(weekday, GETDATE())-1) > 0; SELECT @debugMessage = 'Looping through our list... there''s ' + CAST(COUNT(*) AS VARCHAR(10)) + ' indexes to defrag!' FROM #indexDefragList; IF @debugMode = 1 RAISERROR(@debugMessage, 0, 42) WITH NoWait; /* Begin our loop for defragging */ WHILE (SELECT COUNT(*) FROM #indexDefragList WHERE defragStatus = 0) > 0 BEGIN IF @debugMode = 1 RAISERROR(' Picking an index to beat into shape...', 0, 42) WITH NoWait; /* Grab the most fragmented index first to defrag */ SELECT TOP 1 @objectID = objectID , @indexID = indexID , @databaseID = databaseID , @databaseName = databaseName , @fragmentation = fragmentation , @partitionNumber = partitionNumber , @pageCount = page_count FROM #indexDefragList WHERE defragStatus = 0 ORDER BY fragmentation DESC; IF @debugMode = 1 RAISERROR(' Looking up the specifics for our index...', 0, 42) WITH NoWait; /* Look up index information */ SELECT @updateSQL = N'Update idl Set schemaName = QuoteName(s.name) , objectName = QuoteName(o.name) , indexName = QuoteName(i.name) From #indexDefragList As idl Inner Join ' + @databaseName + '.sys.objects As o On idl.objectID = o.object_id Inner Join ' + @databaseName + '.sys.indexes As i On o.object_id = i.object_id Inner Join ' + @databaseName + '.sys.schemas As s On o.schema_id = s.schema_id Where o.object_id = ' + CAST(@objectID AS VARCHAR(10)) + ' And i.index_id = ' + CAST(@indexID AS VARCHAR(10)) + ' And i.type > 0 And idl.databaseID = ' + CAST(@databaseID AS VARCHAR(10)); EXECUTE SP_EXECUTESQL @updateSQL; /* Grab our object names */ SELECT @objectName = objectName , @schemaName = schemaName , @indexName = indexName FROM #indexDefragList WHERE objectID = @objectID And indexID = @indexID And databaseID = @databaseID; IF @debugMode = 1 RAISERROR(' Grabbing the partition count...', 0, 42) WITH NoWait; /* Determine if the index is partitioned */ SELECT @partitionSQL = 'Select @partitionCount_OUT = Count(*) From ' + @databaseName + '.sys.partitions Where object_id = ' + CAST(@objectID AS VARCHAR(10)) + ' And index_id = ' + CAST(@indexID AS VARCHAR(10)) + ';' , @partitionSQL_Param = '@partitionCount_OUT int OutPut'; EXECUTE SP_EXECUTESQL @partitionSQL, @partitionSQL_Param, @partitionCount_OUT = @partitionCount OUTPUT; IF @debugMode = 1 RAISERROR(' Seeing if there''s any LOBs to be handled...', 0, 42) WITH NoWait; /* Determine if the table contains LOBs */ SELECT @LOB_SQL = ' Select @containsLOB_OUT = Count(*) From ' + @databaseName + '.sys.columns With (NoLock) Where [object_id] = ' + CAST(@objectID AS VARCHAR(10)) + ' And (system_type_id In (34, 35, 99) Or max_length = -1);' /* system_type_id --> 34 = image, 35 = text, 99 = ntext max_length = -1 --> varbinary(max), varchar(max), nvarchar(max), xml */ , @LOB_SQL_Param = '@containsLOB_OUT int OutPut'; EXECUTE SP_EXECUTESQL @LOB_SQL, @LOB_SQL_Param, @containsLOB_OUT = @containsLOB OUTPUT; IF @debugMode = 1 RAISERROR(' Building our SQL statements...', 0, 42) WITH NoWait; /* If there's not a lot of fragmentation, or if we have a LOB, we should reorganize */ IF @fragmentation < @rebuildThreshold Or @containsLOB >= 1 Or @partitionCount > 1 BEGIN SET @sqlCommand = N'Alter Index ' + @indexName + N' On ' + @databaseName + N'.' + @schemaName + N'.' + @objectName + N' ReOrganize'; /* If our index is partitioned, we should always reorganize */ IF @partitionCount > 1 SET @sqlCommand = @sqlCommand + N' Partition = ' + CAST(@partitionNumber AS NVARCHAR(10)); END; /* If the index is heavily fragmented and doesn't contain any partitions or LOB's, rebuild it */ IF @fragmentation >= @rebuildThreshold And IsNull(@containsLOB, 0) != 1 And @partitionCount <= 1 BEGIN /* Set online rebuild options; requires Enterprise Edition */ IF @onlineRebuild = 1 And @editionCheck = 1 SET @rebuildCommand = N' Rebuild With (Online = On'; ELSE SET @rebuildCommand = N' Rebuild With (Online = Off'; /* Set processor restriction options; requires Enterprise Edition */ IF @maxDopRestriction IS Not Null And @editionCheck = 1 SET @rebuildCommand = @rebuildCommand + N', MaxDop = ' + CAST(@maxDopRestriction AS VARCHAR(2)) + N')'; ELSE SET @rebuildCommand = @rebuildCommand + N')'; SET @sqlCommand = N'Alter Index ' + @indexName + N' On ' + @databaseName + N'.' + @schemaName + N'.' + @objectName + @rebuildCommand; END; /* Are we executing the SQL? If so, do it */ IF @executeSQL = 1 BEGIN IF @debugMode = 1 RAISERROR(' Executing SQL statements...', 0, 42) WITH NoWait; /* Grab the time for logging purposes */ SET @dateTimeStart = GETDATE(); /* Log our actions */ INSERT INTO dbo.dba_indexDefragLog ( databaseID , databaseName , objectID , objectName , indexID , indexName , partitionNumber , fragmentation , page_count , dateTimeStart ) SELECT @databaseID , @databaseName , @objectID , @objectName , @indexID , @indexName , @partitionNumber , @fragmentation , @pageCount , @dateTimeStart; SET @indexDefrag_id = SCOPE_IDENTITY(); /* Execute our defrag! */ EXECUTE SP_EXECUTESQL @sqlCommand; SET @dateTimeEnd = GETDATE(); /* Update our log with our completion time */ UPDATE dbo.dba_indexDefragLog SET dateTimeEnd = @dateTimeEnd , durationSeconds = DATEDIFF(SECOND, @dateTimeStart, @dateTimeEnd) WHERE indexDefrag_id = @indexDefrag_id; /* Just a little breather for the server */ WAITFOR Delay @defragDelay; /* Print if specified to do so */ IF @printCommands = 1 PRINT N'Executed: ' + @sqlCommand; END ELSE /* Looks like we're not executing, just printing the commands */ BEGIN IF @debugMode = 1 RAISERROR(' Printing SQL statements...', 0, 42) WITH NoWait; IF @printCommands = 1 PRINT IsNull(@sqlCommand, 'error!'); END IF @debugMode = 1 RAISERROR(' Updating our index defrag status...', 0, 42) WITH NoWait; /* Update our index defrag list so we know we've finished with that index */ UPDATE #indexDefragList SET defragStatus = 1 WHERE databaseID = @databaseID And objectID = @objectID And indexID = @indexID And partitionNumber = @partitionNumber; END /* Do we want to output our fragmentation results? */ IF @printFragmentation = 1 BEGIN IF @debugMode = 1 RAISERROR(' Displaying fragmentation results...', 0, 42) WITH NoWait; SELECT databaseID , databaseName , objectID , objectName , indexID , indexName , fragmentation , page_count FROM #indexDefragList; END; /* Do we want to rebuild stats? */ IF @rebuildStats = 1 BEGIN WHILE Exists(SELECT TOP 1 * FROM #databaseList WHERE statsStatus = 0) BEGIN /* Build our SQL statement to update stats */ SELECT TOP 1 @rebuildStatsSQL = 'Use [' + databaseName + ']; ' + 'Execute sp_updatestats;' , @rebuildStatsID = databaseID FROM #databaseList WHERE statsStatus = 0; SET @debugMessage = 'Rebuilding Statistics: ' + @rebuildStatsSQL; IF @debugMode = 1 RAISERROR(@debugMessage, 0, 42) WITH NoWait; /* Execute our stats update! */ EXECUTE SP_EXECUTESQL @rebuildStatsSQL; /* Keep track of which databases have been updated */ UPDATE #databaseList SET statsStatus = 1 WHERE databaseID = @rebuildStatsID; END; END; /* When everything is said and done, make sure to get rid of our temp table */ DROP TABLE #indexDefragList; DROP TABLE #databaseList; DROP TABLE #processor; IF @debugMode = 1 RAISERROR('DONE! Thank you for taking care of your indexes! :)', 0, 42) WITH NoWait; SET NOCOUNT OFF; RETURN 0 END Go SET Quoted_Identifier OFF SET ANSI_Nulls ON Go
sp_WhoIsActive
Filed under: Miscellaneous, Presentations, Syndication, T-SQL Scripts
For those who attended the webcast I did with Brent Ozar today, “Getting Started With SQL Server Management Studio,” here’s the link to Adam Machanic’s excellent sp_WhoIsActive stored proc:
Thanks for attending!
Page Internals – Investigation Proc
As many of you know, I like to crawl around in page internals in my free time. It can be very enlightening, or just a good check to make sure that what you think is happening, is actually happening. To help with this process, I’ve created myself a little stored procedure that I can simply pass a few parameters to and have it return the page data for me. So for those who don’t have anything better to do who are as interested in page internals as I am, here’s my proc:
CREATE PROCEDURE dbo.dba_viewPageData_sp /* Declare Parameters */ @databaseName VARCHAR(128) , @tableName VARCHAR(128) = Null -- database.schema.tableName , @indexName VARCHAR(128) = Null , @fileNumber INT = Null , @pageNumber INT = Null , @printOption INT = 3 -- 0, 1, 2, or 3 , @pageType CHAR(4) = 'Leaf' -- Leaf, Root, or IAM AS /********************************************************************************* Name: dba_viewPageData_sp Author: Michelle Ufford Purpose: Retrieves page data for the specified table/page. Notes: Can pass either the table name or the pageID, but must pass one, or you'll end up with no results. If the table name is passed, it will return the first page. @tableName must be '<databaseName>.<schemaName>.<tableName>' in order to function correctly for cross-database joins. @printOption can be one of following values: 0 - print just the page header 1 - page header plus per-row hex dumps and a dump of the page slot array 2 - page header plus whole page hex dump 3 - page header plus detailed per-row interpretation Page Options borrowed from: https://blogs.msdn.com/sqlserverstorageengine/archive/2006/06/10/625659.aspx @pageType must be one of the following values: Leaf - returns the first page of the leaf level of your index or heap Root - returns the root page of your index IAM - returns the index allocation map chain for your index or heap Conversions borrowed from: http://sqlskills.com/blogs/paul/post/Inside-The-Storage-Engine- sp_AllocationMetadata-putting-undocumented-system-catalog-views-to-work.aspx Called by: DBA Date User Description ---------------------------------------------------------------------------- 2009-05-06 MFU Initial release for public consumption ********************************************************************************* Exec dbo.dba_viewPageData_sp @databaseName = 'AdventureWorks' , @tableName = 'AdventureWorks.Sales.SalesOrderDetail' , @indexName = 'IX_SalesOrderDetail_ProductID' --, @fileNumber = 1 --, @pageNumber = 38208 , @printOption = 3 , @pageType = 'Root'; *********************************************************************************/ SET NOCOUNT ON; SET XACT_Abort ON; SET Ansi_Padding ON; SET Ansi_Warnings ON; SET ArithAbort ON; SET Concat_Null_Yields_Null ON; SET Numeric_RoundAbort OFF; BEGIN DECLARE @fileID INT , @pageID INT , @sqlStatement NVARCHAR(1200) , @sqlParameters NVARCHAR(255) , @errorMessage VARCHAR(100); BEGIN Try IF @fileNumber IS Null And @pageNumber IS Null And @tableName IS Null BEGIN SET @errorMessage = 'You must provide either a file/page number, or a table name!'; RAISERROR(@errorMessage, 16, 1); END; IF @pageType Not In ('Leaf', 'Root', 'IAM') BEGIN SET @errorMessage = 'You have entered an invalid page type; valid options are "Leaf", "Root", or "IAM"'; RAISERROR(@errorMessage, 16, 1); END; IF @fileNumber IS Null Or @pageNumber IS Null BEGIN SET @sqlStatement = CASE WHEN @pageType = 'Leaf' THEN 'Select Top 1 @p_fileID = Convert (varchar(6), Convert (int, SubString (au.first_page, 6, 1) + SubString (au.first_page, 5, 1))) , @p_pageID = Convert (varchar(20), Convert (int, SubString (au.first_page, 4, 1) + SubString (au.first_page, 3, 1) + SubString (au.first_page, 2, 1) + SubString (au.first_page, 1, 1)))' WHEN @pageType = 'Root' THEN 'Select Top 1 @p_fileID = Convert (varchar(6), Convert (int, SubString (au.root_page, 6, 1) + SubString (au.root_page, 5, 1))) , @p_pageID = Convert (varchar(20), Convert (int, SubString (au.root_page, 4, 1) + SubString (au.root_page, 3, 1) + SubString (au.root_page, 2, 1) + SubString (au.root_page, 1, 1)))' WHEN @pageType = 'IAM' THEN 'Select Top 1 @p_fileID = Convert (varchar(6), Convert (int, SubString (au.first_iam_page, 6, 1) + SubString (au.first_iam_page, 5, 1))) , @p_pageID = Convert (varchar(20), Convert (int, SubString (au.first_iam_page, 4, 1) + SubString (au.first_iam_page, 3, 1) + SubString (au.first_iam_page, 2, 1) + SubString (au.first_iam_page, 1, 1)))' END + 'From ' + QUOTENAME(PARSENAME(@databaseName, 1)) + '.sys.indexes AS i Join ' + QUOTENAME(PARSENAME(@databaseName, 1)) + '.sys.partitions AS p On i.[object_id] = p.[object_id] And i.index_id = p.index_id Join ' + QUOTENAME(PARSENAME(@databaseName, 1)) + '.sys.system_internals_allocation_units AS au On p.hobt_id = au.container_id Where p.[object_id] = Object_ID(@p_tableName) And au.first_page > 0x000000000000 ' + CASE WHEN @indexName IS Null THEN ';' ELSE 'And i.name = @p_indexName;' END; SET @sqlParameters = '@p_tableName varchar(128) , @p_indexName varchar(128) , @p_fileID int OUTPUT , @p_pageID int OUTPUT'; EXECUTE SP_EXECUTESQL @sqlStatement , @sqlParameters , @p_tableName = @tableName , @p_indexName = @indexName , @p_fileID = @fileID OUTPUT , @p_pageID = @pageID OUTPUT; END ELSE BEGIN SELECT @fileID = @fileNumber , @pageID = @pageNumber; END; DBCC TraceOn (3604); DBCC Page (@databaseName, @fileID, @pageID, @printOption); DBCC TraceOff (3604); END Try BEGIN Catch PRINT @errorMessage; END Catch; SET NOCOUNT OFF; RETURN 0; END Go
This proc does have cross-database support, i.e. you can install it in your DBA database and use it to investigate data in other databases. Here’s an example…
EXEC dbo.dba_viewPageData_sp @databaseName = 'AdventureWorks' , @tableName = 'AdventureWorks.Sales.SalesOrderDetail' , @indexName = 'IX_SalesOrderDetail_ProductID';
… will return a nice data page:
DBCC execution completed. If DBCC printed error messages, contact your system administrator. PAGE: (1:11000) BUFFER: BUF @0x0391F140 bpage = 0x0C0C0000 bhash = 0x00000000 bpageno = (1:11000) bdbid = 7 breferences = 0 bUse1 = 35177 bstat = 0x1c00009 blog = 0x21212159 bnext = 0x00000000
[waits for the "oohs" and "aahs" to subside...]
I also give you the option to specify a specific page, in case you want to follow the page trail (i.e. m_nextPage). I’m not really providing support for partitions, although I do have a little dirty piece of code to return a hobt with data if possible (i.e. “first_page > 0×000000000000″).
Update: Special thanks to Jeremiah Peschka and Adam Machanic for showing me
QUOTENAME(PARSENAME(@databaseName, 1))!
Also, thanks to Paul Randal for his excellent blog posts on this very topic! Check out his blog post on DBCC Page. The conversion code was borrowed from his sp_AllocationMetadata proc.
Update 2: I’ve made some quick changes based on some feedback from Twitter. Thanks for the suggestions and hopefully you enjoy the updates.
Happy crawling!
A Look at Missing Indexes
Filed under: Performance & Tuning, Syndication, T-SQL Scripts
Tim Ford (@SQLAgentMan) recently blogged about his Top 5 SQL Server Indexing Best Practices. I thought it was a good list, and it inspired this blog post. I’ve recently been doing a little index spring cleaning, and I thought some people may be interested in the process I go through. So, here it is… a journey through madness an overview of my general missing index process.
I start with my trusty dba_missingIndexStoredProc table. If this table sounds completely foreign to you, check out my post, Find Missing Indexes In Stored Procs. Basically, I have a process that runs every night, scanning the XML of every query plan on the server to find procs that are possibly missing indexes. I then log the details for later action.
So I take a look at my table, and I find 8 stored procedures that are possibly missing indexes. Clicking on the XML link will show me the logged query plan:
Right clicking on the “Missing Index” description will give me the details of the recommended index:
Here’s an example of what SQL Server will return for you:
/* Missing Index Details from ExecutionPlan2.sqlplan The Query Processor estimates that implementing the following index could improve the query cost by 85.7327%. */ /* USE [msdb] GO CREATE NONCLUSTERED INDEX [<Name of Missing Index, sysname,>] ON [dbo].[sysjobhistory] ([job_id]) INCLUDE ([instance_id],[step_id],[sql_message_id],[sql_severity], [run_status],[run_date],[run_time],[run_duration],[operator_id_emailed], [operator_id_netsent],[operator_id_paged],[retries_attempted],[server]) GO */
I now compare the details of this proposed index to the missing index DMV suggestions, using this query:
SELECT t.name AS 'affected_table' , 'Create NonClustered Index IX_' + t.name + '_missing_' + CAST(ddmid.index_handle AS VARCHAR(10)) + ' On ' + ddmid.STATEMENT + ' (' + IsNull(ddmid.equality_columns,'') + CASE WHEN ddmid.equality_columns IS Not Null And ddmid.inequality_columns IS Not Null THEN ',' ELSE '' END + IsNull(ddmid.inequality_columns, '') + ')' + IsNull(' Include (' + ddmid.included_columns + ');', ';' ) AS sql_statement , ddmigs.user_seeks , ddmigs.user_scans , CAST((ddmigs.user_seeks + ddmigs.user_scans) * ddmigs.avg_user_impact AS INT) AS 'est_impact' , ddmigs.last_user_seek FROM sys.dm_db_missing_index_groups AS ddmig INNER JOIN sys.dm_db_missing_index_group_stats AS ddmigs ON ddmigs.group_handle = ddmig.index_group_handle INNER JOIN sys.dm_db_missing_index_details AS ddmid ON ddmig.index_handle = ddmid.index_handle INNER JOIN sys.tables AS t ON ddmid.OBJECT_ID = t.OBJECT_ID WHERE ddmid.database_id = DB_ID() --AND t.name = 'myTableName' ORDER BY CAST((ddmigs.user_seeks + ddmigs.user_scans) * ddmigs.avg_user_impact AS INT) DESC;
I usually find the data in both places, but not always. One reason why is because the missing index DMV will only store data since your last reboot. So if I’m taking a look at this DMV on Monday and I just rebooted on Sunday, I may not have enough history to give me meaningful recommendations. This is just something to be aware of.
What I’m looking for in this DMV is the number of user_seeks and the est_impact. Also, if I haven’t rebooted my server in a while, I take a look at last_user_seek so I can determine whether or not it’s still accurate.
Next, I take a look at my existing indexes using Kimberly Tripp’s sp_helpindex2 system stored proc. I use her proc instead of sp_helpindex because I need to see included columns.
If you’re wondering why I’m looking at existing indexes, the reason is because I’m looking for indexes that can be modified slightly to accommodate my missing index needs. By “modified slightly,” I mean that I’d only want to make a change to an existing index if it did not drastically change the size or composition of an index, i.e. adding one or two narrow columns as included columns. I do NOT mean making changes that double the size of your index; in those cases, you’d probably be better off creating a brand new index.
Looking at existing indexes is actually a pretty critical part of the puzzle. If I have a proc that only gets called a few times an hour and could benefit from a better index, I may not create that index if it means adding a wide, expensive index to a busy table. If I can make a small modification to an existing index, then there’s a greater chance I’ll make the change and cover my query.
At this point, I should have enough information to start making decisions. I was going to write out the path I normally take when making decisions, but I thought, “Hey! What a great time for a diagram.” So here you go:
Disclaimer: I’m *not* a Visio wizard, so if I butchered the use of certain symbols in my diagram, please let me know so I can a) fix it, and b) learn from it!
It’s hard to really put all of the decision paths into a single, small diagram like this. There’s a lot of variables that I’m not even touching here. But I think this is a fairly good “generic” representation of the path I take. When I hit an “end” process, it means I don’t create the missing index at this time. Maybe in the future, it’ll become necessary, but I prefer to err on the side of less indexes.
So there you have it, a brief look at my missing index process. Hopefully someone finds it helpful.
Automated Index Defrag Script
Filed under: Performance & Tuning, SQL 2008, SQL Tips, T-SQL Scripts
Note: This script has been updated. You can find the latest version here: http://sqlfool.com/2009/06/index-defrag-script-v30/
So after much delay, here’s the latest and greatest version of my index defrag script.
A summary of the changes:
- Added support for centralized execution. Option to defrag indexes for a single database from another database, or for all non-system databases.
- Consolidated Enterprise and Standard versions of the script with new @editionCheck variable.
- Added parametrization for MaxDop restrictions during rebuilds; validates that the value does not exceed the actual number of processors on the server.
- Changed minimum fragmentation default value from 10 to 5 to match BOL recommendations.
- Limited defrags to objects with more than 8 pages.
- Added a debug option to give a little more insight into what’s happening and to assist with troubleshooting.
- Updated logic for handling partitions and LOBs.
And a couple of notes and explanations:
Don’t you know you can just pass NULL to sys.dm_db_index_physical_stats for the DatabaseID?
Yes, I realize you can do this. But I don’t want to defrag the system databases, i.e. tempdb, so I opted to handle it this way instead.
How long will this take?
It depends. I don’t necessarily recommend running it without specifying a database; at least, not unmonitored. You *can* do that, but it could take a while. For example, to run sys.dm_db_index_physical_stats for all databases and tables, totaling 2TB, took me 4.5 hours; that doesn’t even count the actual defrags.
Where should I put this?
It’s up to you. If you have a database for items like centralized maintenance or scratch tables, that may be a good place for it. If you prefer, you could also put this in each individual database and call it locally, too. I would not put this in the master or msdb databases.
This is pretty close to a complete rewrite, so please let me know if you encounter any bugs. And now… the code!
IF Not Exists(SELECT [OBJECT_ID] FROM sys.tables WHERE name = N'dba_indexDefragLog') BEGIN -- Drop Table dbo.dba_indexDefragLog CREATE TABLE dbo.dba_indexDefragLog ( indexDefrag_id INT IDENTITY(1,1) Not Null , databaseID INT Not Null , databaseName NVARCHAR(128) Not Null , objectID INT Not Null , objectName NVARCHAR(128) Not Null , indexID INT Not Null , indexName NVARCHAR(128) Not Null , partitionNumber SMALLINT Not Null , fragmentation FLOAT Not Null , page_count INT Not Null , dateTimeStart DATETIME Not Null , durationSeconds INT Not Null CONSTRAINT PK_indexDefragLog PRIMARY KEY CLUSTERED (indexDefrag_id) ) PRINT 'dba_indexDefragLog Table Created'; END IF OBJECTPROPERTY(OBJECT_ID('dbo.dba_indexDefrag_sp'), N'IsProcedure') = 1 BEGIN DROP PROCEDURE dbo.dba_indexDefrag_sp; PRINT 'Procedure dba_indexDefrag_sp dropped'; END; Go CREATE PROCEDURE dbo.dba_indexDefrag_sp /* Declare Parameters */ @minFragmentation FLOAT = 5.0 /* in percent, will not defrag if fragmentation less than specified */ , @rebuildThreshold FLOAT = 30.0 /* in percent, greater than @rebuildThreshold will result in rebuild instead of reorg */ , @executeSQL BIT = 1 /* 1 = execute; 0 = print command only */ , @DATABASE VARCHAR(128) = Null /* Option to specify a database name; null will return all */ , @tableName VARCHAR(4000) = Null -- databaseName.schema.tableName /* Option to specify a table name; null will return all */ , @onlineRebuild BIT = 1 /* 1 = online rebuild; 0 = offline rebuild; only in Enterprise */ , @maxDopRestriction TINYINT = Null /* Option to restrict the number of processors for the operation; only in Enterprise */ , @printCommands BIT = 0 /* 1 = print commands; 0 = do not print commands */ , @printFragmentation BIT = 0 /* 1 = print fragmentation prior to defrag; 0 = do not print */ , @defragDelay CHAR(8) = '00:00:05' /* time to wait between defrag commands */ , @debugMode BIT = 0 /* display some useful comments to help determine if/where issues occur */ AS /********************************************************************************* Name: dba_indexDefrag_sp Author: Michelle Ufford, http://sqlfool.com Purpose: Defrags all indexes for one or more databases Notes: CAUTION: TRANSACTION LOG SIZE MUST BE MONITORED CLOSELY WHEN DEFRAGMENTING. @minFragmentation defaulted to 10%, will not defrag if fragmentation is less than that @rebuildThreshold defaulted to 30% as recommended by Microsoft in BOL; greater than 30% will result in rebuild instead @executeSQL 1 = execute the SQL generated by this proc; 0 = print command only @database Optional, specify specific database name to defrag; If not specified, all non-system databases will be defragged. @tableName Specify if you only want to defrag indexes for a specific table, format = databaseName.schema.tableName; if not specified, all tables will be defragged. @onlineRebuild 1 = online rebuild; 0 = offline rebuild @maxDopRestriction Option to specify a processor limit for index rebuilds @printCommands 1 = print commands to screen; 0 = do not print commands @printFragmentation 1 = print fragmentation to screen; 0 = do not print fragmentation @defragDelay time to wait between defrag commands; gives the server a little time to catch up @debugMode 1 = display debug comments; helps with troubleshooting 0 = do not display debug comments Called by: SQL Agent Job or DBA Date Initials Description ---------------------------------------------------------------------------- 2008-10-27 MFU Initial Release for public consumption 2008-11-17 MFU Added page-count to log table , added @printFragmentation option 2009-03-17 MFU Provided support for centralized execution, , consolidated Enterprise & Standard versions , added @debugMode, @maxDopRestriction , modified LOB and partition logic ********************************************************************************* Exec dbo.dba_indexDefrag_sp @executeSQL = 0 , @minFragmentation = 80 , @printCommands = 1 , @debugMode = 1 , @printFragmentation = 1 , @database = 'AdventureWorks' , @tableName = 'AdventureWorks.Sales.SalesOrderDetail'; *********************************************************************************/ SET NOCOUNT ON; SET XACT_Abort ON; SET Quoted_Identifier ON; BEGIN IF @debugMode = 1 RAISERROR('Dusting off the spiderwebs and starting up...', 0, 42) WITH NoWait; /* Declare our variables */ DECLARE @objectID INT , @databaseID INT , @databaseName NVARCHAR(128) , @indexID INT , @partitionCount BIGINT , @schemaName NVARCHAR(128) , @objectName NVARCHAR(128) , @indexName NVARCHAR(128) , @partitionNumber SMALLINT , @partitions SMALLINT , @fragmentation FLOAT , @pageCount INT , @sqlCommand NVARCHAR(4000) , @rebuildCommand NVARCHAR(200) , @dateTimeStart DATETIME , @dateTimeEnd DATETIME , @containsLOB BIT , @editionCheck BIT , @debugMessage VARCHAR(128) , @updateSQL NVARCHAR(4000) , @partitionSQL NVARCHAR(4000) , @partitionSQL_Param NVARCHAR(1000) , @LOB_SQL NVARCHAR(4000) , @LOB_SQL_Param NVARCHAR(1000); /* Create our temporary tables */ CREATE TABLE #indexDefragList ( databaseID INT , databaseName NVARCHAR(128) , objectID INT , indexID INT , partitionNumber SMALLINT , fragmentation FLOAT , page_count INT , defragStatus BIT , schemaName NVARCHAR(128) Null , objectName NVARCHAR(128) Null , indexName NVARCHAR(128) Null ); CREATE TABLE #databaseList ( databaseID INT , databaseName VARCHAR(128) ); CREATE TABLE #processor ( [INDEX] INT , Name VARCHAR(128) , Internal_Value INT , Character_Value INT ); IF @debugMode = 1 RAISERROR('Beginning validation...', 0, 42) WITH NoWait; /* Just a little validation... */ IF @minFragmentation Not Between 0.00 And 100.0 SET @minFragmentation = 5.0; IF @rebuildThreshold Not Between 0.00 And 100.0 SET @rebuildThreshold = 30.0; IF @defragDelay Not Like '00:[0-5][0-9]:[0-5][0-9]' SET @defragDelay = '00:00:05'; /* Make sure we're not exceeding the number of processors we have available */ INSERT INTO #processor EXECUTE XP_MSVER 'ProcessorCount'; IF @maxDopRestriction IS Not Null And @maxDopRestriction > (SELECT Internal_Value FROM #processor) SELECT @maxDopRestriction = Internal_Value FROM #processor; /* Check our server version; 1804890536 = Enterprise, 610778273 = Enterprise Evaluation, -2117995310 = Developer */ IF (SELECT SERVERPROPERTY('EditionID')) In (1804890536, 610778273, -2117995310) SET @editionCheck = 1 -- supports online rebuilds ELSE SET @editionCheck = 0; -- does not support online rebuilds IF @debugMode = 1 RAISERROR('Grabbing a list of our databases...', 0, 42) WITH NoWait; /* Retrieve the list of databases to investigate */ INSERT INTO #databaseList SELECT database_id , name FROM sys.databases WHERE name = IsNull(@DATABASE, name) And database_id > 4 -- exclude system databases And [STATE] = 0; -- state must be ONLINE IF @debugMode = 1 RAISERROR('Looping through our list of databases and checking for fragmentation...', 0, 42) WITH NoWait; /* Loop through our list of databases */ WHILE (SELECT COUNT(*) FROM #databaseList) > 0 BEGIN SELECT TOP 1 @databaseID = databaseID FROM #databaseList; SELECT @debugMessage = ' working on ' + DB_NAME(@databaseID) + '...'; IF @debugMode = 1 RAISERROR(@debugMessage, 0, 42) WITH NoWait; /* Determine which indexes to defrag using our user-defined parameters */ INSERT INTO #indexDefragList SELECT database_id AS databaseID , QUOTENAME(DB_NAME(database_id)) AS 'databaseName' , [OBJECT_ID] AS objectID , index_id AS indexID , partition_number AS partitionNumber , avg_fragmentation_in_percent AS fragmentation , page_count , 0 AS 'defragStatus' /* 0 = unprocessed, 1 = processed */ , Null AS 'schemaName' , Null AS 'objectName' , Null AS 'indexName' FROM sys.dm_db_index_physical_stats (@databaseID, OBJECT_ID(@tableName), Null , Null, N'Limited') WHERE avg_fragmentation_in_percent >= @minFragmentation And index_id > 0 -- ignore heaps And page_count > 8 -- ignore objects with less than 1 extent OPTION (MaxDop 1); DELETE FROM #databaseList WHERE databaseID = @databaseID; END CREATE CLUSTERED INDEX CIX_temp_indexDefragList ON #indexDefragList(databaseID, objectID, indexID, partitionNumber); SELECT @debugMessage = 'Looping through our list... there''s ' + CAST(COUNT(*) AS VARCHAR(10)) + ' indexes to defrag!' FROM #indexDefragList; IF @debugMode = 1 RAISERROR(@debugMessage, 0, 42) WITH NoWait; /* Begin our loop for defragging */ WHILE (SELECT COUNT(*) FROM #indexDefragList WHERE defragStatus = 0) > 0 BEGIN IF @debugMode = 1 RAISERROR(' Picking an index to beat into shape...', 0, 42) WITH NoWait; /* Grab the most fragmented index first to defrag */ SELECT TOP 1 @objectID = objectID , @indexID = indexID , @databaseID = databaseID , @databaseName = databaseName , @fragmentation = fragmentation , @partitionNumber = partitionNumber , @pageCount = page_count FROM #indexDefragList WHERE defragStatus = 0 ORDER BY fragmentation DESC; IF @debugMode = 1 RAISERROR(' Looking up the specifics for our index...', 0, 42) WITH NoWait; /* Look up index information */ SELECT @updateSQL = N'Update idl Set schemaName = QuoteName(s.name) , objectName = QuoteName(o.name) , indexName = QuoteName(i.name) From #indexDefragList As idl Inner Join ' + @databaseName + '.sys.objects As o On idl.objectID = o.object_id Inner Join ' + @databaseName + '.sys.indexes As i On o.object_id = i.object_id Inner Join ' + @databaseName + '.sys.schemas As s On o.schema_id = s.schema_id Where o.object_id = ' + CAST(@objectID AS VARCHAR(10)) + ' And i.index_id = ' + CAST(@indexID AS VARCHAR(10)) + ' And i.type > 0 And idl.databaseID = ' + CAST(@databaseID AS VARCHAR(10)); EXECUTE SP_EXECUTESQL @updateSQL; /* Grab our object names */ SELECT @objectName = objectName , @schemaName = schemaName , @indexName = indexName FROM #indexDefragList WHERE objectID = @objectID And indexID = @indexID And databaseID = @databaseID; IF @debugMode = 1 RAISERROR(' Grabbing the partition count...', 0, 42) WITH NoWait; /* Determine if the index is partitioned */ SELECT @partitionSQL = 'Select @partitionCount_OUT = Count(*) From ' + @databaseName + '.sys.partitions Where object_id = ' + CAST(@objectID AS VARCHAR(10)) + ' And index_id = ' + CAST(@indexID AS VARCHAR(10)) + ';' , @partitionSQL_Param = '@partitionCount_OUT int OutPut'; EXECUTE SP_EXECUTESQL @partitionSQL, @partitionSQL_Param, @partitionCount_OUT = @partitionCount OUTPUT; IF @debugMode = 1 RAISERROR(' Seeing if there''s any LOBs to be handled...', 0, 42) WITH NoWait; /* Determine if the table contains LOBs */ SELECT @LOB_SQL = ' Select Top 1 @containsLOB_OUT = column_id From ' + @databaseName + '.sys.columns With (NoLock) Where [object_id] = ' + CAST(@objectID AS VARCHAR(10)) + ' And (system_type_id In (34, 35, 99) Or max_length = -1);' /* system_type_id --> 34 = image, 35 = text, 99 = ntext max_length = -1 --> varbinary(max), varchar(max), nvarchar(max), xml */ , @LOB_SQL_Param = '@containsLOB_OUT int OutPut'; EXECUTE SP_EXECUTESQL @LOB_SQL, @LOB_SQL_Param, @containsLOB_OUT = @containsLOB OUTPUT; IF @debugMode = 1 RAISERROR(' Building our SQL statements...', 0, 42) WITH NoWait; /* If there's not a lot of fragmentation, or if we have a LOB, we should reorganize */ IF @fragmentation < @rebuildThreshold Or @containsLOB = 1 Or @partitionCount > 1 BEGIN SET @sqlCommand = N'Alter Index ' + @indexName + N' On ' + @databaseName + N'.' + @schemaName + N'.' + @objectName + N' ReOrganize'; /* If our index is partitioned, we should always reorganize */ IF @partitionCount > 1 SET @sqlCommand = @sqlCommand + N' Partition = ' + CAST(@partitionNumber AS NVARCHAR(10)); END; /* If the index is heavily fragmented and doesn't contain any partitions or LOB's, rebuild it */ IF @fragmentation >= @rebuildThreshold And IsNull(@containsLOB, 0) != 1 And @partitionCount <= 1 BEGIN /* Set online rebuild options; requires Enterprise Edition */ IF @onlineRebuild = 1 And @editionCheck = 1 SET @rebuildCommand = N' Rebuild With (Online = On'; ELSE SET @rebuildCommand = N' Rebuild With (Online = Off'; /* Set processor restriction options; requires Enterprise Edition */ IF @maxDopRestriction IS Not Null And @editionCheck = 1 SET @rebuildCommand = @rebuildCommand + N', MaxDop = ' + CAST(@maxDopRestriction AS VARCHAR(2)) + N')'; ELSE SET @rebuildCommand = @rebuildCommand + N')'; SET @sqlCommand = N'Alter Index ' + @indexName + N' On ' + @databaseName + N'.' + @schemaName + N'.' + @objectName + @rebuildCommand; END; /* Are we executing the SQL? If so, do it */ IF @executeSQL = 1 BEGIN IF @debugMode = 1 RAISERROR(' Executing SQL statements...', 0, 42) WITH NoWait; /* Grab the time for logging purposes */ SET @dateTimeStart = GETDATE(); EXECUTE SP_EXECUTESQL @sqlCommand; SET @dateTimeEnd = GETDATE(); /* Log our actions */ INSERT INTO dbo.dba_indexDefragLog ( databaseID , databaseName , objectID , objectName , indexID , indexName , partitionNumber , fragmentation , page_count , dateTimeStart , durationSeconds ) SELECT @databaseID , @databaseName , @objectID , @objectName , @indexID , @indexName , @partitionNumber , @fragmentation , @pageCount , @dateTimeStart , DATEDIFF(SECOND, @dateTimeStart, @dateTimeEnd); /* Just a little breather for the server */ WAITFOR Delay @defragDelay; /* Print if specified to do so */ IF @printCommands = 1 PRINT N'Executed: ' + @sqlCommand; END ELSE /* Looks like we're not executing, just printing the commands */ BEGIN IF @debugMode = 1 RAISERROR(' Printing SQL statements...', 0, 42) WITH NoWait; IF @printCommands = 1 PRINT IsNull(@sqlCommand, 'error!'); END IF @debugMode = 1 RAISERROR(' Updating our index defrag status...', 0, 42) WITH NoWait; /* Update our index defrag list so we know we've finished with that index */ UPDATE #indexDefragList SET defragStatus = 1 WHERE databaseID = @databaseID And objectID = @objectID And indexID = @indexID And partitionNumber = @partitionNumber; END /* Do we want to output our fragmentation results? */ IF @printFragmentation = 1 BEGIN IF @debugMode = 1 RAISERROR(' Displaying fragmentation results...', 0, 42) WITH NoWait; SELECT databaseID , databaseName , objectID , objectName , indexID , indexName , fragmentation , page_count FROM #indexDefragList; END; /* When everything is said and done, make sure to get rid of our temp table */ DROP TABLE #indexDefragList; DROP TABLE #databaseList; DROP TABLE #processor; IF @debugMode = 1 RAISERROR('DONE! Thank you for taking care of your indexes! :)', 0, 42) WITH NoWait; SET NOCOUNT OFF; RETURN 0 END Go
Thanks to my beta testers, @scoinva, @davidmtate, @jdanton, and @SuperCoolMoss!
Special thanks to SCM for keeping on me to finish this.
Happy Defragging!
Michelle
Source: http://sqlfool.com/2009/03/automated-index-defrag-script/
Find Missing Indexes in Stored Procs with T-SQL
Filed under: Performance & Tuning, SQL Tips, Syndication, T-SQL Scripts
This post should probably be called “The Power of Twitter.” I’ve said it before, I’ll say it again: I love Twitter. I mostly follow SQL Server people, so it’s become a great source of new information and help when I feel like banging my head against the wall when I get stumped.
So last week, Jonathan Kehayias (@jmkehayias) posted a link to a missing index script on the MSDN forums. Jonathan’s script is modified from something he put together for a question posed by Jeremiah Peschka (@peschkaj).
Jonathan’s script intrigued me. I’d never tried to search a query plan’s XML before, and it certainly presents some interesting possibilities. After dealing with a missing index in production a few weeks ago (caused by an index change), I thought it’d be a great idea to put a regular monitor in place.
Everything was going well until I ran into a problem where I couldn’t get the proc name returned. The results spanned numerous databases; I had the object_id and database_id, but I wanted to store the proc name instead. I tried several different methods, including sp_msforeachdb and sp_executeSQL, and while I had a working solution, it was a little more clunky than I liked. So I asked my awesome followers on Twitter for any tips and within minutes I had half a dozen responses. In the end, @MladenPrajdic solved my problem with a pretty simple solution: put ‘Use ?;’ at the start of my sp_msforeachdb statement. Thanks again, Mladen!
I’ve now had this process running on my server for a few days now, with good success. The stored procedure below will return the database name, proc name, and query plan XML for any stored proc with a missing index. This is a centralized proc that will store the results in a table for later action. If you click on the XML, you should see the actual query plan with the missing index details. Because this looks at cached query plans, your best bet is to run it fairly regularly (maybe daily) to increase your chances of catching any problem procs.
/* Create a stored procedure skeleton */ IF OBJECTPROPERTY(OBJECT_ID('dbo.dba_missingIndexStoredProc_sp'), N'IsProcedure') IS Null BEGIN EXECUTE ('Create Procedure dbo.dba_missingIndexStoredProc_sp As Print ''Hello World!''') RAISERROR('Procedure dba_missingIndexStoredProc_sp created.', 10, 1); END; Go /* Drop our table if it already exists */ IF Exists(SELECT OBJECT_ID FROM sys.tables WHERE [name] = N'dba_missingIndexStoredProc') BEGIN DROP TABLE dbo.dba_missingIndexStoredProc PRINT 'dba_missingIndexStoredProc table dropped!'; END /* Create our table */ CREATE TABLE dbo.dba_missingIndexStoredProc ( missingIndexSP_id INT IDENTITY(1,1) Not Null , databaseName VARCHAR(128) Not Null , databaseID INT Not Null , objectName VARCHAR(128) Not Null , objectID INT Not Null , query_plan xml Not Null , executionDate SMALLDATETIME Not Null CONSTRAINT PK_missingIndexStoredProc PRIMARY KEY CLUSTERED(missingIndexSP_id) ); PRINT 'dba_missingIndexStoredProc Table Created'; /* Configure our settings */ SET ANSI_Nulls ON; SET Quoted_Identifier ON; Go ALTER PROCEDURE dbo.dba_missingIndexStoredProc_sp /* Declare Parameters */ @lastExecuted_inDays INT = 7 , @minExecutionCount INT = 7 , @logResults BIT = 1 , @displayResults BIT = 0 AS /********************************************************************************* Name: dba_missingIndexStoredProc_sp Author: Michelle Ufford, http://sqlfool.com Purpose: Retrieves stored procedures with missing indexes in their cached query plans. @lastExecuted_inDays = number of days old the cached query plan can be to still appear in the results; the HIGHER the number, the longer the execution time. @minExecutionCount = minimum number of executions the cached query plan can have to still appear in the results; the LOWER the number, the longer the execution time. @logResults = store results in dba_missingIndexStoredProc @displayResults = return results to the caller Notes: This is not 100% guaranteed to catch all missing indexes in a stored procedure. It will only catch it if the stored proc's query plan is still in cache. Run regularly to help minimize the chance of missing a proc. Called by: DBA and/or SQL Agent Job Date User Description ---------------------------------------------------------------------------- 2009-03-02 MFU Initial Release for public consumption ********************************************************************************* Exec dbo.dba_missingIndexStoredProc_sp @lastExecuted_inDays = 30 , @minExecutionCount = 5 , @logResults = 1 , @displayResults = 1; *********************************************************************************/ SET NOCOUNT ON; SET XACT_Abort ON; SET Ansi_Padding ON; SET Ansi_Warnings ON; SET ArithAbort ON; SET Concat_Null_Yields_Null ON; SET Numeric_RoundAbort OFF; BEGIN /* Declare Variables */ DECLARE @currentDateTime SMALLDATETIME; SET @currentDateTime = GETDATE(); DECLARE @plan_handles TABLE ( plan_handle VARBINARY(64) Not Null ); CREATE TABLE #missingIndexes ( databaseID INT Not Null , objectID INT Not Null , query_plan xml Not Null CONSTRAINT PK_temp_missingIndexes PRIMARY KEY CLUSTERED ( databaseID, objectID ) ); BEGIN Try /* Perform some data validation */ IF @logResults = 0 And @displayResults = 0 BEGIN /* Log the fact that there were open transactions */ EXECUTE dbo.dba_logError_sp @errorType = 'app' , @app_errorProcedure = 'dba_missingIndexStoredProc_sp' , @app_errorMessage = '@logResults = 0 and @displayResults = 0; no action taken, exiting stored proc.' , @forceExit = 1 , @returnError = 1; END; BEGIN TRANSACTION; /* Retrieve distinct plan handles to minimize dm_exec_query_plan lookups */ INSERT INTO @plan_handles SELECT DISTINCT plan_handle FROM sys.dm_exec_query_stats WHERE last_execution_time > DATEADD(DAY, -@lastExecuted_inDays, @currentDateTime) And execution_count > @minExecutionCount; WITH xmlNameSpaces ( DEFAULT 'http://schemas.microsoft.com/sqlserver/2004/07/showplan' ) /* Retrieve our query plan's XML if there's a missing index */ INSERT INTO #missingIndexes SELECT deqp.[dbid] , deqp.objectid , deqp.query_plan FROM @plan_handles AS ph Cross Apply sys.dm_exec_query_plan(ph.plan_handle) AS deqp WHERE deqp.query_plan.exist('//MissingIndex') = 1 And deqp.objectid IS Not Null; /* Do we want to store the results of our process? */ IF @logResults = 1 BEGIN INSERT INTO dbo.dba_missingIndexStoredProc EXECUTE sp_msForEachDB 'Use ?; Select ''?'' , mi.databaseID , Object_Name(o.object_id) , o.object_id , mi.query_plan , GetDate() From sys.objects As o Join #missingIndexes As mi On o.object_id = mi.objectID Where databaseID = DB_ID();'; END /* We're not logging it, so let's display it */ ELSE BEGIN EXECUTE sp_msForEachDB 'Use ?; Select ''?'' , mi.databaseID , Object_Name(o.object_id) , o.object_id , mi.query_plan , GetDate() From sys.objects As o Join #missingIndexes As mi On o.object_id = mi.objectID Where databaseID = DB_ID();'; END; /* See above; this part will only work if we've logged our data. */ IF @displayResults = 1 And @logResults = 1 BEGIN SELECT * FROM dbo.dba_missingIndexStoredProc WHERE executionDate >= @currentDateTime; END; /* If you have an open transaction, commit it */ IF @@TRANCOUNT > 0 COMMIT TRANSACTION; END Try BEGIN Catch /* Whoops, there was an error... rollback! */ IF @@TRANCOUNT > 0 ROLLBACK TRANSACTION; /* Return an error message and log it */ EXECUTE dbo.dba_logError_sp; END Catch; /* Clean-Up! */ DROP TABLE #missingIndexes; SET NOCOUNT OFF; RETURN 0; END Go
Not know what “EXECUTE dbo.dba_logError_sp;” is doing? Check out my blog post on Error Handling in T-SQL.
HTH!
Michelle








