How can I automate statistics management?
Occasionally, it can be beneficial to turn off AUTO_CREATE_STATISTICS and AUTO_UPDATE_STATISTICS, and manage these items yourself.
I’ve created the following stored procedure, which lives in master to allow it to be called from the context of some other database. This stored procedure can be added to a SQL Server Agent Job allowing it to run periodically.
The first time the stored proc runs, it creates a dbo.StatsHistory table in MSDB which tracks updates made by the proc. If you create a “Utilities” filegroup in MSDB prior to running the stored proc the first time, the dbo.StatsHistory is automatically created on that filegroup.
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 |
USE master; IF EXISTS ( SELECT 1 FROM sys.schemas s INNER JOIN sys.objects o ON s.schema_id = o.schema_id WHERE s.name = 'dbo' AND o.name = 'sp_UpdateAllStats' ) BEGIN DROP PROCEDURE dbo.sp_UpdateAllStats; END GO CREATE PROCEDURE dbo.sp_UpdateAllStats ( @MinHoursSinceLastUpdate INT = 0 , @ShowCmd BIT = 1 , @DebugOnly BIT = 0 ) AS BEGIN /* Updates statistics for all objects in the current database. Date: 2015-11-25 By: Max Vernon NOTE: Stored Proc must be created in the [master] database, and must be marked as a "system procedure" to enable proper functionality. EXEC sys.sp_MS_marksystemobject dbo.UpdateStats; Version History: 1.0 Initial Version 1.1 Reduced noise messages 1.2 creates StatsHistory table on correct filegroup */ SET NOCOUNT ON; SET ANSI_WARNINGS ON; DECLARE @cmd NVARCHAR(MAX); DECLARE @dsName NVARCHAR(MAX); DECLARE @ObjectID INT; DECLARE @StatsID INT; DECLARE @SchemaName SYSNAME; DECLARE @ObjectName SYSNAME; DECLARE @StatsName SYSNAME; DECLARE @StatsDate DATETIME; DECLARE @StartTime DATETIME; DECLARE @EndTime DATETIME; DECLARE @Rows INT; DECLARE @RowsSampled INT; DECLARE @ModificationCounter INT; DECLARE @DatabaseName SYSNAME; DECLARE @Action VARCHAR(50); SET @DatabaseName = DB_NAME(); IF NOT EXISTS( SELECT 1 FROM msdb.sys.schemas s INNER JOIN msdb.sys.objects o ON s.schema_id = o.schema_id WHERE s.name = 'dbo' AND o.name = 'StatsHistory' ) BEGIN /* get the data_spaces.name independent of the collation and case */ SELECT @dsName = ds.name FROM msdb.sys.data_spaces ds WHERE ds.name = 'Utilities' COLLATE SQL_Latin1_General_CP1_CI_AS; IF @dsName IS NULL SET @dsName = 'PRIMARY'; SET @cmd = ' CREATE TABLE dbo.StatsHistory ( StatsHistoryID INT NOT NULL CONSTRAINT PK_StatsHistory PRIMARY KEY CLUSTERED IDENTITY(1,1) , StatsHistoryDate DATETIME NOT NULL CONSTRAINT DF_StatsHistory_StatsHistoryDate DEFAULT (GETDATE()) , DatabaseName SYSNAME NOT NULL , SchemaName SYSNAME NOT NULL , ObjectName SYSNAME NOT NULL , StatsName SYSNAME NOT NULL , UpdateDate DATETIME NULL , UpdateDurationMs INT NULL , Rows INT NOT NULL , RowsSampled INT NULL , ModificationCounter INT NULL , Action VARCHAR(50) NOT NULL ) ON [' + @dsName + '];'; EXEC msdb.sys.sp_executesql @cmd; END SET @cmd = ''; DECLARE cur CURSOR LOCAL FORWARD_ONLY FOR WITH StatsDetails AS ( SELECT ObjectID = o.object_id , SchemaName = sch.name , ObjectName = o.name , StatsName = st.name , StatsID = st.stats_id , StatsDate = dsp.last_updated , Rows = dsp.rows , RowsSampled = dsp.rows_sampled , ModificationCounter = dsp.modification_counter /* number of modifications to the stat's leading column that have been modified since the last stats update */ , UpdateStatement = 'UPDATE STATISTICS ' + quotename(sch.name) + '.' + quotename(o.name) + '(' + quotename(st.name) + ') WITH FULLSCAN' + CASE WHEN st.no_recompute = 1 THEN ', NORECOMPUTE' ELSE '' END + ';' FROM sys.schemas sch INNER JOIN sys.objects o ON sch.schema_id = o.schema_id INNER JOIN sys.stats st ON o.object_id = st.object_id OUTER APPLY sys.dm_db_stats_properties(o.object_id, st.stats_id) dsp WHERE o.is_ms_shipped = 0 ) SELECT sd.ObjectID , sd.StatsID , sd.SchemaName , sd.ObjectName , sd.StatsName , sd.UpdateStatement , sd.StatsDate , sd.Rows , sd.RowsSampled , sd.ModificationCounter FROM StatsDetails sd ORDER BY sd.SchemaName , sd.ObjectName , sd.StatsID; OPEN cur; FETCH NEXT FROM cur INTO @ObjectID , @StatsID , @SchemaName , @ObjectName , @StatsName , @cmd , @StatsDate , @Rows , @RowsSampled , @ModificationCounter; WHILE @@FETCH_STATUS = 0 BEGIN IF @ShowCmd = 1 BEGIN PRINT ('Processing Stats: ' + @SchemaName + '.' + @ObjectName + '.' + @StatsName); END SET @Action = ''; IF COALESCE(@Rows, 0) = 0 BEGIN /* sys.dm_db_stats_properties may return NULL values if the stats have never been updated. Get the current row count for the object. */ SET ANSI_WARNINGS OFF; SELECT @Rows = SUM(ips.record_count) FROM ( SELECT record_count = ips.record_count FROM sys.dm_db_index_physical_stats(DB_ID(), @ObjectID, NULL, NULL, 'SAMPLED') ips UNION ALL SELECT 0 /* ensure NULL is never returned to @Rows */ ) ips SET ANSI_WARNINGS ON; END IF COALESCE(@Rows, 0) > 0 AND ((@StatsDate IS NULL) OR DATEDIFF(HOUR, @StatsDate, GETDATE()) > @MinHoursSinceLastUpdate) BEGIN SET @StartTime = GETDATE(); /* only update the statistics if rows have been modified. @ModificationCounter will be NULL if the statistics object has never been updated via UPDATE STATISTICS */ IF @ShowCmd = 1 AND COALESCE(@ModificationCounter, 1) > 0 BEGIN PRINT (CHAR(9) + 'Last updated ' + CASE WHEN @StatsDate IS NULL THEN '(never)' ELSE CONVERT(VARCHAR(50), @StatsDate, 120) END + '.'); PRINT (CHAR(9) + 'Modifications since last stats update: ' + CONVERT(VARCHAR(50), @ModificationCounter)); PRINT (CHAR(9) + 'Will update stats using:'); PRINT (CHAR(9) + @cmd); END IF COALESCE(@ModificationCounter, 1) = 0 BEGIN SET @Action = 'ZeroModificationsSinceLastUpdate'; IF @ShowCmd = 1 BEGIN PRINT (CHAR(9) + 'Zero modifications since last update on ' + CASE WHEN @StatsDate IS NULL THEN '(never)' ELSE CONVERT(VARCHAR(50), @StatsDate, 120) END + '.'); END END IF @DebugOnly = 0 AND COALESCE(@ModificationCounter, 1) > 0 BEGIN EXEC sp_executesql @cmd; SET @Action = 'Updated'; END SET @EndTime = GETDATE(); IF @DebugOnly = 0 BEGIN SELECT @StatsDate = COALESCE(dsp.last_updated, GETDATE()) , @Rows = COALESCE(dsp.rows, 0) , @RowsSampled = COALESCE(dsp.rows_sampled, 0) /* Leave this out since it will be zero at this point. The value from prior to executing UPDATE STATISTICS shows the number of rows modified since the last time stats were updated, and is useful to save in the dbo.StatsHistory table; the below code clobbers that value. , @ModificationCounter = COALESCE(dsp.modification_counter, 0) */ FROM sys.schemas sch INNER JOIN sys.objects o ON sch.schema_id = o.schema_id INNER JOIN sys.stats st ON o.object_id = st.object_id OUTER APPLY sys.dm_db_stats_properties(o.object_id, st.stats_id) dsp WHERE sch.name = @SchemaName AND o.name = @ObjectName AND st.name = @StatsName; INSERT INTO msdb.dbo.StatsHistory (DatabaseName, SchemaName, ObjectName, StatsName, UpdateDate, UpdateDurationMs, Rows, RowsSampled, ModificationCounter, Action) VALUES (@DatabaseName, @SchemaName, @ObjectName, @StatsName, @StatsDate, DATEDIFF(MILLISECOND, @StartTime, @EndTime), @Rows, @RowsSampled, @ModificationCounter, @Action); END ELSE BEGIN SET @Action = 'DebugMode'; INSERT INTO msdb.dbo.StatsHistory (DatabaseName, SchemaName, ObjectName, StatsName, UpdateDate, UpdateDurationMs, Rows, RowsSampled, ModificationCounter, Action) VALUES (@DatabaseName, @SchemaName, @ObjectName, @StatsName, @StatsDate, DATEDIFF(MILLISECOND, @StartTime, @EndTime), @Rows, @RowsSampled, @ModificationCounter, @Action); END END ELSE BEGIN IF COALESCE(@Rows, 0) = 0 BEGIN IF @ShowCmd = 1 BEGIN PRINT (CHAR(9) + 'Contains zero rows. Stats will not be updated.'); END SET @Action = 'ContainsZeroRows'; INSERT INTO msdb.dbo.StatsHistory (DatabaseName, SchemaName, ObjectName, StatsName, UpdateDate, UpdateDurationMs, Rows, RowsSampled, ModificationCounter, Action) VALUES (@DatabaseName, @SchemaName, @ObjectName, @StatsName, @StatsDate, DATEDIFF(MILLISECOND, @StartTime, @EndTime), @Rows, @RowsSampled, @ModificationCounter, @Action); END ELSE BEGIN IF @ShowCmd = 1 BEGIN PRINT (CHAR(9) + 'Last updated ' + CASE WHEN @StatsDate IS NULL THEN '(never)' ELSE CONVERT(VARCHAR(50), @StatsDate, 120) END + '.'); PRINT (CHAR(9) + 'SKIPPING'); END SET @Action = 'UpdatedTooRecently'; INSERT INTO msdb.dbo.StatsHistory (DatabaseName, SchemaName, ObjectName, StatsName, UpdateDate, UpdateDurationMs, Rows, RowsSampled, ModificationCounter, Action) VALUES (@DatabaseName, @SchemaName, @ObjectName, @StatsName, @StatsDate, DATEDIFF(MILLISECOND, @StartTime, @EndTime), @Rows, @RowsSampled, @ModificationCounter, @Action); END END IF @ShowCmd = 1 BEGIN PRINT (''); /* add a blank line between output rows */ END FETCH NEXT FROM cur INTO @ObjectID , @StatsID , @SchemaName , @ObjectName , @StatsName , @cmd , @StatsDate , @Rows , @RowsSampled , @ModificationCounter; END CLOSE cur; DEALLOCATE cur; END GO EXEC sys.sp_MS_marksystemobject 'dbo.sp_UpdateAllStats'; GO |
Hopefully you’ll find the above code useful. Let me know if you have questions!