DBCC CLONEDATABASE is a good thing.

But sometimes its too broadly scoped to be useful, especially between organizations.

What if I need to troubleshoot a single query from (a) known, shared schema(s) when there are 20,000 + statistics and some may contain sensitive data in the range_hi key values?

Below is a tool that can help, provided the system is SQL Server 2016 SP2 or higher, the Query Store is enabled and captured the relevant plan, and the Legacy CE was NOT used to compile the plan. This stored procedure in that case takes the plan_id and retrieves from the Query Store and SHOW_STATISTICS commands what is needed to generate UPDATE STATISTICS statements including stats_stream, rowcount, and pagecount.

The basic mining of optimizer stats from Query Store for 2016 SP2 ++ can be seen here...

Harvesting SQL Server optimizer stats detail from Query Plan XML: Part II SQL Server 2016 SP2++

<a href="https://sql-sasquatch.blogspot.com/2018/11/harvesting-sql-server-optimizer-stats.html">https://sql-sasquatch.blogspot.com/2018/11/harvesting-sql-server-optimizer-stats.html</a> CREATE OR ALTER PROCEDURE sasquatch__xfer_one_plan_stats @plan_id INT AS /* stored procedure based on work explained in the following blog post https://sql-sasquatch.blogspot.com/2018/11/harvesting-sql-server-optimizer-stats.html supply a plan_id from the Query Store in @plan_id, and if SQL Server version is 2016 SP2 or higher AND if the Legacy CE was NOT used UPDATE STATISTICS commands for each of the stats used to compile the plan will be generated */ DECLARE @startdb NVARCHAR(256), @db NVARCHAR(256), @schema NVARCHAR(256), @table NVARCHAR(256), @stats NVARCHAR(256), @cmd NVARCHAR(MAX); SET @startdb = DB_NAME(); DROP TABLE IF EXISTS #plan; CREATE TABLE #plan(planXML XML); INSERT INTO #plan SELECT CONVERT(XML, query_plan) planXML FROM sys.query_store_plan WHERE plan_id = @plan_id; ;WITH XMLNAMESPACES(default 'http://schemas.microsoft.com/sqlserver/2004/07/showplan') SELECT dbName, schemaName, tableName, statName, CONVERT(VARBINARY(MAX), NULL) [stats_stream], CONVERT(BIGINT, NULL) [rowcount], CONVERT(BIGINT, NULL) [pagecount] INTO #QO_stats FROM #plan CROSS APPLY planXML.nodes(N'/ShowPlanXML/BatchSequence/Batch/Statements/StmtSimple/QueryPlan/OptimizerStatsUsage') qp(qpnode) CROSS APPLY qpnode.nodes(N'StatisticsInfo') qp2(statsinfo) CROSS APPLY (SELECT qp2.statsinfo.value(N'@Statistics', N'varchar(max)')) statName(statName) CROSS APPLY (SELECT qp2.statsinfo.value(N'@Table', N'varchar(max)')) tableName(tableName) CROSS APPLY (SELECT qp2.statsinfo.value(N'@Schema', N'varchar(max)')) schemaName(schemaName) CROSS APPLY (SELECT qp2.statsinfo.value(N'@Database', N'varchar(max)')) dbName(dbName) OPTION (MAXDOP 1); CREATE TABLE #one_stat ([stats_stream] VARBINARY(MAX), [rowcount] BIGINT, [pagecount] BIGINT); WHILE EXISTS (SELECT TOP 1 1 FROM #QO_stats WHERE [stats_stream] IS NULL) BEGIN SELECT TOP 1 @db = dbName, @schema = schemaName, @table = tableName, @stats = statName FROM #QO_stats WHERE [stats_stream] IS NULL ORDER BY dbName, schemaName, tableName, statName; SET @cmd = N'USE ' + @db + N' DBCC SHOW_STATISTICS(''' + @schema + N'.' + @table + N''', ' + @stats + N') WITH STATS_STREAM, NO_INFOMSGS' INSERT INTO #one_stat EXEC (@cmd); UPDATE #QO_stats SET [stats_stream] = os.[stats_stream], [rowcount] = os.[rowcount], [pagecount] = os.[pagecount] FROM #one_stat os WHERE @db = #QO_stats.dbName AND @schema = #QO_stats.schemaName AND @table = #QO_stats.tableName AND @stats = #QO_stats.statName; TRUNCATE TABLE #one_stat; END SELECT N'USE ' + qo.dbName + N' UPDATE STATISTICS ' + qo.schemaName + N'.' + qo.tableName + N'(' + qo.statName + N') WITH ' + CASE WHEN qo.[pagecount] IS NULL THEN '' ELSE N'PAGECOUNT = ' + CONVERT(NVARCHAR(20), qo.[pagecount]) + N', ' END + CASE WHEN qo.[rowcount] IS NULL THEN '' ELSE N'ROWCOUNT = ' + CONVERT(NVARCHAR(20), qo.[rowcount]) + N', ' END + N'STATS_STREAM = ' + CONVERT(NVARCHAR(MAX), qo.[stats_stream], 1) FROM #QO_stats qo; EXEC (N'USE ' + @startDB); /* 20181205 */

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本文标题:Fun with SQL Server Query Store, Query Plan 'StatisticsInfo' XML nodes, and STAT ...

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