Préface
Tôt ou tard, un administrateur de BDD souhaiterait disposer d'un indicateur de performance pour les requêtes SQL Server. Comme nous le savons tous, l'exécution de Profiler pendant 24 heures entraînera une charge système considérable et, par conséquent, elle ne peut pas être considérée comme une solution optimale pour les bases de données utilisées en mode 24/7.
Alors, comment détecter l'état des requêtes SQL Server ? Comment pouvons-nous exécuter une trace pour les problèmes détectés liés aux requêtes sans intervention humaine ?
Dans cet article, je fournirai une implémentation de l'indicateur de performance SQL Server pour les requêtes, les procédures stockées et les déclencheurs, ainsi que son utilisation pour l'exécution de la trace.
Solution
Voyons tout d'abord la démarche générale de mise en place de l'indicateur de performance pour les requêtes, les procédures stockées et les triggers :
- Création des tableaux requis pour la collecte et l'analyse des informations
- Création d'une vue pour la collecte d'informations.
- Création de procédures stockées pour la collecte d'informations.
- Création d'une vue pour la sortie d'informations.
Et maintenant, considérons la mise en œuvre :
1. Création des tableaux requis pour la collecte et l'analyse des informations.
1.1. Pour les requêtes :
USE [DATABASE_NAME] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO SET ANSI_PADDING ON GO CREATE TABLE [srv].[SQL_StatementExecStat]( [ID] [bigint] IDENTITY(1,1) NOT NULL, [InsertDate] [datetime] NULL, [QueryHash] [binary](8) NULL, [ExecutionCount] [bigint] NULL, [TotalWorkerTime] [bigint] NULL, [StatementText] [nvarchar](max) NULL, [TotalElapsedTime] [bigint] NULL, CONSTRAINT [PK_SQL_StatementExecStat] PRIMARY KEY CLUSTERED ( [ID] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY] GO SET ANSI_PADDING ON GO
1.2. Pour les procédures stockées :
USE [DATABASE_NAME] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [srv].[SQL_ProcedureExecStat]( [ID] [bigint] IDENTITY(1,1) NOT NULL, [InsertDate] [datetime] NULL, [database_id] [int] NULL, [object_id] [int] NULL, [ExecutionCount] [bigint] NULL, [TotalWorkerTime] [bigint] NULL, [TotalElapsedTime] [bigint] NULL, [TotalPhysicalReads] [bigint] NULL, [TotalLogicalReads] [bigint] NULL, [TotalLogicalWrites] [bigint] NULL, CONSTRAINT [PK_SQL_ProcedureExecStat] PRIMARY KEY CLUSTERED ( [ID] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] GO
1.3. Pour les déclencheurs :
USE [DATABASE_NAME] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [srv].[SQL_TriggerExecStat]( [ID] [bigint] IDENTITY(1,1) NOT NULL, [InsertDate] [datetime] NULL, [database_id] [int] NULL, [object_id] [int] NULL, [ExecutionCount] [bigint] NULL, [TotalWorkerTime] [bigint] NULL, [TotalElapsedTime] [bigint] NULL ) ON [PRIMARY] GO
2. Création d'une vue pour la collecte d'informations (ici, nous pouvons insérer des filtres pour éliminer les informations non pertinentes (par exemple, les requêtes et les procédures avec déclencheurs de réplication, etc.).
2.1. Pour les requêtes :
USE [DATABASE_NAME] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE view [srv].[vStatementExecInfo] as with info as ( SELECT query_stats.query_hash AS QueryHash, SUM(query_stats.total_worker_time ) / SUM(query_stats.execution_count) AS AvgCPU_Time, SUM(query_stats.execution_count ) AS ExecutionCount, SUM(query_stats.total_worker_time ) AS TotalWorkerTime, MIN(query_stats.statement_text ) AS StatementText, MIN(query_stats.min_worker_time ) AS MinWorkerTime, MAX(query_stats.max_worker_time ) AS MaxWorkerTime, SUM(query_stats.total_physical_reads) AS TotalPhysicalReads, MIN(query_stats.min_physical_reads ) AS MinPhysicalReads, MAX(query_stats.max_physical_reads ) AS MaxPhysicalReads, SUM(query_stats.total_physical_reads) / SUM(query_stats.execution_count) AS AvgPhysicalReads, SUM(query_stats.total_logical_writes) AS TotalLogicalWrites, MIN(query_stats.min_logical_writes ) AS MinLogicalWrites, MAX(query_stats.max_logical_writes ) AS MaxLogicalWrites, SUM(query_stats.total_logical_writes) / SUM(query_stats.execution_count) AS AvgLogicalWrites, SUM(query_stats.total_logical_reads ) AS TotalLogicalReads, MIN(query_stats.min_logical_reads ) AS MinLogicalReads, MAX(query_stats.max_logical_reads ) AS MaxLogicalReads, SUM(query_stats.total_logical_reads ) / SUM(query_stats.execution_count) AS AvgLogicalReads, SUM(query_stats.total_elapsed_time ) AS TotalElapsedTime, MIN(query_stats.min_elapsed_time ) AS MinElapsedTime, MAX(query_stats.max_elapsed_time ) AS MaxElapsedTime, SUM(query_stats.total_elapsed_time ) / SUM(query_stats.execution_count) AS AvgElapsedTime, MIN(query_stats.creation_time ) AS MinCreationTime, MAX(query_stats.last_execution_time ) AS LastExecuteTime FROM (SELECT QS.query_hash ,QS.total_worker_time ,QS.execution_count ,QS.min_worker_time ,QS.max_worker_time ,QS.min_physical_reads ,QS.max_physical_reads ,QS.total_physical_reads ,QS.total_logical_writes ,QS.min_logical_writes ,QS.max_logical_writes ,QS.min_logical_reads ,QS.max_logical_reads ,QS.total_logical_reads ,QS.min_elapsed_time ,QS.max_elapsed_time ,QS.total_elapsed_time ,QS.creation_time ,QS.last_execution_time ,SUBSTRING(ST.text, (QS.statement_start_offset/2) + 1, ((CASE statement_end_offset WHEN -1 THEN DATALENGTH(ST.text) ELSE QS.statement_end_offset END - QS.statement_start_offset)/2) + 1) AS statement_text FROM sys.dm_exec_query_stats AS QS CROSS APPLY sys.dm_exec_sql_text(QS.sql_handle) as ST) as query_stats WHERE execution_count > 1 and last_execution_time >= dateadd(hour,-3,getdate()) GROUP BY query_stats.query_hash) select QueryHash, AvgCPU_Time, ExecutionCount, TotalWorkerTime, StatementText, MinWorkerTime, MaxWorkerTime, TotalPhysicalReads, MinPhysicalReads, MaxPhysicalReads, AvgPhysicalReads, TotalLogicalWrites, MinLogicalWrites, MaxLogicalWrites, AvgLogicalWrites, TotalLogicalReads, MinLogicalReads, MaxLogicalReads, AvgLogicalReads, TotalElapsedTime, MinElapsedTime, MaxElapsedTime, AvgElapsedTime, MinCreationTime, LastExecuteTime from info GO
Ici, les requêtes système suivantes sont utilisées :sys.dm_exec_query_stats et sys.dm_exec_sql_text.
2.2. Pour les procédures stockées :
USE [DATABASE_NAME] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE view [srv].[vProcedureExecInfo] as with info as ( SELECT procedure_stats.database_id AS database_id, procedure_stats.object_id AS object_id, MIN(procedure_stats.type) AS type, SUM(procedure_stats.total_worker_time ) / SUM(procedure_stats.execution_count) AS AvgCPU_Time, SUM(procedure_stats.execution_count ) AS ExecutionCount, SUM(procedure_stats.total_worker_time ) AS TotalWorkerTime, MIN(procedure_stats.ProcedureText ) AS ProcedureText, MIN(procedure_stats.min_worker_time ) AS MinWorkerTime, MAX(procedure_stats.max_worker_time ) AS MaxWorkerTime, SUM(procedure_stats.total_physical_reads) AS TotalPhysicalReads, MIN(procedure_stats.min_physical_reads ) AS MinPhysicalReads, MAX(procedure_stats.max_physical_reads ) AS MaxPhysicalReads, SUM(procedure_stats.total_physical_reads) / SUM(procedure_stats.execution_count) AS AvgPhysicalReads, SUM(procedure_stats.total_logical_writes) AS TotalLogicalWrites, MIN(procedure_stats.min_logical_writes ) AS MinLogicalWrites, MAX(procedure_stats.max_logical_writes ) AS MaxLogicalWrites, SUM(procedure_stats.total_logical_writes) / SUM(procedure_stats.execution_count) AS AvgLogicalWrites, SUM(procedure_stats.total_logical_reads ) AS TotalLogicalReads, MIN(procedure_stats.min_logical_reads ) AS MinLogicalReads, MAX(procedure_stats.max_logical_reads ) AS MaxLogicalReads, SUM(procedure_stats.total_logical_reads ) / SUM(procedure_stats.execution_count) AS AvgLogicalReads, SUM(procedure_stats.total_elapsed_time ) AS TotalElapsedTime, MIN(procedure_stats.min_elapsed_time ) AS MinElapsedTime, MAX(procedure_stats.max_elapsed_time ) AS MaxElapsedTime, SUM(procedure_stats.total_elapsed_time ) / SUM(procedure_stats.execution_count) AS AvgElapsedTime, MIN(procedure_stats.cached_time ) AS MinCachedTime, MAX(procedure_stats.last_execution_time ) AS LastExecuteTime FROM (SELECT QS.database_id ,QS.object_id ,QS.type ,QS.total_worker_time ,QS.execution_count ,QS.min_worker_time ,QS.max_worker_time ,QS.min_physical_reads ,QS.max_physical_reads ,QS.total_physical_reads ,QS.total_logical_writes ,QS.min_logical_writes ,QS.max_logical_writes ,QS.min_logical_reads ,QS.max_logical_reads ,QS.total_logical_reads ,QS.min_elapsed_time ,QS.max_elapsed_time ,QS.total_elapsed_time ,QS.cached_time ,QS.last_execution_time ,ST.text as Proceduretext FROM sys.dm_exec_Procedure_stats AS QS CROSS APPLY sys.dm_exec_sql_text(QS.sql_handle) as ST) as procedure_stats WHERE execution_count > 1 and last_execution_time >= dateadd(hour,-3,getdate()) GROUP BY database_id,object_id) select database_id, object_id, type, AvgCPU_Time, ExecutionCount, TotalWorkerTime, ProcedureText, MinWorkerTime, MaxWorkerTime, TotalPhysicalReads, MinPhysicalReads, MaxPhysicalReads, AvgPhysicalReads, TotalLogicalWrites, MinLogicalWrites, MaxLogicalWrites, AvgLogicalWrites, TotalLogicalReads, MinLogicalReads, MaxLogicalReads, AvgLogicalReads, TotalElapsedTime, MinElapsedTime, MaxElapsedTime, AvgElapsedTime, MinCachedTime, LastExecuteTime from info GO
Ici, les requêtes système suivantes sont utilisées :sys.dm_exec_Procedure_stats et sys.dm_exec_sql_text.
2.3. Pour les déclencheurs :
USE [DATABASE_NAME] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE view [srv].[vTriggerExecInfo] as with info as ( SELECT procedure_stats.database_id AS database_id, procedure_stats.object_id AS object_id, MIN(procedure_stats.type) AS type, SUM(procedure_stats.total_worker_time ) / SUM(procedure_stats.execution_count) AS AvgCPU_Time, SUM(procedure_stats.execution_count ) AS ExecutionCount, SUM(procedure_stats.total_worker_time ) AS TotalWorkerTime, MIN(procedure_stats.ProcedureText ) AS ProcedureText, MIN(procedure_stats.min_worker_time ) AS MinWorkerTime, MAX(procedure_stats.max_worker_time ) AS MaxWorkerTime, SUM(procedure_stats.total_physical_reads) AS TotalPhysicalReads, MIN(procedure_stats.min_physical_reads ) AS MinPhysicalReads, MAX(procedure_stats.max_physical_reads ) AS MaxPhysicalReads, SUM(procedure_stats.total_physical_reads) / SUM(procedure_stats.execution_count) AS AvgPhysicalReads, SUM(procedure_stats.total_logical_writes) AS TotalLogicalWrites, MIN(procedure_stats.min_logical_writes ) AS MinLogicalWrites, MAX(procedure_stats.max_logical_writes ) AS MaxLogicalWrites, SUM(procedure_stats.total_logical_writes) / SUM(procedure_stats.execution_count) AS AvgLogicalWrites, SUM(procedure_stats.total_logical_reads ) AS TotalLogicalReads, MIN(procedure_stats.min_logical_reads ) AS MinLogicalReads, MAX(procedure_stats.max_logical_reads ) AS MaxLogicalReads, SUM(procedure_stats.total_logical_reads ) / SUM(procedure_stats.execution_count) AS AvgLogicalReads, SUM(procedure_stats.total_elapsed_time ) AS TotalElapsedTime, MIN(procedure_stats.min_elapsed_time ) AS MinElapsedTime, MAX(procedure_stats.max_elapsed_time ) AS MaxElapsedTime, SUM(procedure_stats.total_elapsed_time ) / SUM(procedure_stats.execution_count) AS AvgElapsedTime, MIN(procedure_stats.cached_time ) AS MinCachedTime, MAX(procedure_stats.last_execution_time ) AS LastExecuteTime FROM (SELECT QS.database_id ,QS.object_id ,QS.type ,QS.total_worker_time ,QS.execution_count ,QS.min_worker_time ,QS.max_worker_time ,QS.min_physical_reads ,QS.max_physical_reads ,QS.total_physical_reads ,QS.total_logical_writes ,QS.min_logical_writes ,QS.max_logical_writes ,QS.min_logical_reads ,QS.max_logical_reads ,QS.total_logical_reads ,QS.min_elapsed_time ,QS.max_elapsed_time ,QS.total_elapsed_time ,QS.cached_time ,QS.last_execution_time ,ST.text as Proceduretext FROM sys.dm_exec_trigger_stats AS QS CROSS APPLY sys.dm_exec_sql_text(QS.sql_handle) as ST) as procedure_stats WHERE execution_count > 1 and last_execution_time >= dateadd(hour,-3,getdate()) GROUP BY database_id,object_id) select database_id, object_id, type, AvgCPU_Time, ExecutionCount, TotalWorkerTime, ProcedureText, MinWorkerTime, MaxWorkerTime, TotalPhysicalReads, MinPhysicalReads, MaxPhysicalReads, AvgPhysicalReads, TotalLogicalWrites, MinLogicalWrites, MaxLogicalWrites, AvgLogicalWrites, TotalLogicalReads, MinLogicalReads, MaxLogicalReads, AvgLogicalReads, TotalElapsedTime, MinElapsedTime, MaxElapsedTime, AvgElapsedTime, MinCachedTime, LastExecuteTime from info GO
Ici, les requêtes système suivantes sont utilisées :sys.dm_exec_trigger_stats et sys.dm_exec_sql_text.
3. Création de procédures stockées pour la collecte d'informations.
3.1. Pour les requêtes :
USE [DATABASE_NAME] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE PROCEDURE [srv].[InsertForSQL_StatementExecStat] @koef decimal(12,2)=0.0 –collection coefficient --is picked in an experimental way for more exact collection, --in most cases, we can put 0.0, --if frequency of the collection running does not exceed 5 minutes. --Accuracy of calculation depends on the collection frequency and collection coefficient. --The more frequent collection running is, the less influence collection coefficient has. AS BEGIN SET NOCOUNT ON; declare @AvgCPU_Time bigint ,@MaxAvgCPU_Time bigint ,@AvgTotalWorkerTime bigint ,@MaxTotalWorkerTime bigint ,@AvgAvgElapsedTime bigint ,@MaxAvgElapsedTime bigint ,@AvgTotalElapsedTime bigint ,@MaxTotalElapsedTime bigint select @AvgCPU_Time = AVG(AvgCPU_Time), @MaxAvgCPU_Time = max(AvgCPU_Time), @AvgTotalWorkerTime = AVG(TotalWorkerTime), @MaxTotalWorkerTime = max(TotalWorkerTime), @AvgAvgElapsedTime = AVG(AvgElapsedTime), @MaxAvgElapsedTime = max(AvgElapsedTime), @AvgTotalElapsedTime = AVG(TotalElapsedTime), @MaxTotalElapsedTime = max(TotalElapsedTime) from srv.vStatementExecInfo; insert into srv.SQL_StatementExecStat ( [InsertDate] ,[QueryHash] ,[ExecutionCount] ,[TotalWorkerTime] ,[StatementText] ,[TotalElapsedTime]) select getdate() ,[QueryHash] ,[ExecutionCount] ,[TotalWorkerTime] ,[StatementText] ,[TotalElapsedTime] from srv.vStatementExecInfo where(AvgCPU_Time > @AvgCPU_Time + @koef * (@MaxAvgCPU_Time - @AvgCPU_Time)) or (TotalWorkerTime > @AvgTotalWorkerTime + @koef * (@MaxTotalWorkerTime - @AvgTotalWorkerTime)) or (AvgElapsedTime > @AvgAvgElapsedTime + @koef * (@MaxAvgElapsedTime - @AvgAvgElapsedTime)) or (TotalElapsedTime > @AvgTotalElapsedTime + @koef * (@MaxTotalElapsedTime - @AvgTotalElapsedTime)); END GO
3.2. Pour les procédures stockées :
USE [DATABASE_NAME] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE PROCEDURE [srv].[InsertForProcedureExecStat] @koef decimal(12,2)=0.0 --collection coefficient --is picked in an experimental way for more exact collection, --in most cases, we can put 0.0, -- if frequency of the collection running does not exceed 5 minutes. --Accuracy of calculation depends on the collection frequency and collection coefficient. --The more frequent collection running is, the less influence collection coefficient has. AS BEGIN SET NOCOUNT ON; declare @AvgCPU_Time bigint ,@MaxAvgCPU_Time bigint ,@AvgTotalWorkerTime bigint ,@MaxTotalWorkerTime bigint ,@AvgAvgElapsedTime bigint ,@MaxAvgElapsedTime bigint ,@AvgTotalElapsedTime bigint ,@MaxTotalElapsedTime bigint; select @AvgCPU_Time = AVG(AvgCPU_Time), @MaxAvgCPU_Time = max(AvgCPU_Time), @AvgTotalWorkerTime = AVG(TotalWorkerTime), @MaxTotalWorkerTime = max(TotalWorkerTime), @AvgAvgElapsedTime = AVG(AvgElapsedTime), @MaxAvgElapsedTime = max(AvgElapsedTime), @AvgTotalElapsedTime = AVG(TotalElapsedTime), @MaxTotalElapsedTime = max(TotalElapsedTime) from srv.vProcedureExecInfo; insert into srv.SQL_ProcedureExecStat ( [InsertDate] ,database_id ,object_id ,[ExecutionCount] ,[TotalWorkerTime] ,[TotalElapsedTime] ,[TotalPhysicalReads] ,[TotalLogicalReads] ,[TotalLogicalWrites]) select getdate() ,database_id ,object_id ,[ExecutionCount] ,[TotalWorkerTime] ,[TotalElapsedTime] ,[TotalPhysicalReads] ,[TotalLogicalReads] ,[TotalLogicalWrites] from srv.vProcedureExecInfo where(AvgCPU_Time > @AvgCPU_Time + @koef * (@MaxAvgCPU_Time - @AvgCPU_Time)) or (TotalWorkerTime > @AvgTotalWorkerTime + @koef * (@MaxTotalWorkerTime - @AvgTotalWorkerTime)) or (AvgElapsedTime > @AvgAvgElapsedTime + @koef * (@MaxAvgElapsedTime - @AvgAvgElapsedTime)) or (TotalElapsedTime > @AvgTotalElapsedTime + @koef * (@MaxTotalElapsedTime - @AvgTotalElapsedTime)); END GO
3.3. Pour les déclencheurs :
USE [DATABASE_NAME] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE PROCEDURE [srv].[InsertForTriggerExecStat] @koef decimal(12,2)=0.0 --collection coefficient --is picked in an experimental way for more exact collection, --in most cases, we can put 0.0, --if frequency of the collection running does not exceed 5 minutes. --Accuracy of calculation depends on the collection frequency and collection coefficient. --The more frequent collection running is, the less influence collection coefficient has. AS BEGIN SET NOCOUNT ON; declare @AvgCPU_Time bigint ,@MaxAvgCPU_Time bigint ,@AvgTotalWorkerTime bigint ,@MaxTotalWorkerTime bigint ,@AvgAvgElapsedTime bigint ,@MaxAvgElapsedTime bigint ,@AvgTotalElapsedTime bigint ,@MaxTotalElapsedTime bigint select @AvgCPU_Time = AVG(AvgCPU_Time), @MaxAvgCPU_Time = max(AvgCPU_Time), @AvgTotalWorkerTime = AVG(TotalWorkerTime), @MaxTotalWorkerTime = max(TotalWorkerTime), @AvgAvgElapsedTime = AVG(AvgElapsedTime), @MaxAvgElapsedTime = max(AvgElapsedTime), @AvgTotalElapsedTime = AVG(TotalElapsedTime), @MaxTotalElapsedTime = max(TotalElapsedTime) from srv.vProcedureExecInfo; insert into srv.SQL_TriggerExecStat ( [InsertDate] ,database_id ,object_id ,[ExecutionCount] ,[TotalWorkerTime] ,[TotalElapsedTime]) select getdate() ,database_id ,object_id ,[ExecutionCount] ,[TotalWorkerTime] ,[TotalElapsedTime] from srv.vTriggerExecInfo where(AvgCPU_Time > @AvgCPU_Time + @koef * (@MaxAvgCPU_Time - @AvgCPU_Time)) or (TotalWorkerTime > @AvgTotalWorkerTime + @koef * (@MaxTotalWorkerTime - @AvgTotalWorkerTime)) or (AvgElapsedTime > @AvgAvgElapsedTime + @koef * (@MaxAvgElapsedTime - @AvgAvgElapsedTime)) or (TotalElapsedTime > @AvgTotalElapsedTime + @koef * (@MaxTotalElapsedTime - @AvgTotalElapsedTime)); END GO
4. Création d'une vue pour la sortie des informations.
4.1. Pour les requêtes :
USE [DATABASE_NAME] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE VIEW [srv].[vStatementExecTotalInfo] as select ExecutionCount as Num ,TotalWorkerTime as TotalWorkerTime ,TotalElapsedTime as TotalElapsedTime ,convert(decimal(8,2),AvgCPU_Time/1000000.) as AvgWorkerSec ,convert(decimal(8,2),AvgElapsedTime/1000000.) as AvgElapsedSec ,... ,QueryHash ,StatementText from [SRV].[srv].[vStatementExecInfo]; GO
4.2. Pour les procédures stockées :
USE [DATABASE_NAME] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE VIEW [srv].[vProcedureExecTotalInfo] as select ExecutionCount as Num ,TotalWorkerTime as TotalWorkerTime ,TotalElapsedTime as TotalElapsedTime ,convert(decimal(8,2),AvgCPU_Time/1000000.) as AvgWorkerSec ,convert(decimal(8,2),AvgElapsedTime/1000000.) as AvgElapsedSec ,... ,database_id ,object_id ,db_name(database_id) as DB_Name ,OBJECT_SCHEMA_NAME(object_id, database_id) as Schema_Name ,object_name(object_id, database_id) as Procedure_Name from [SRV].[srv].[vProcedureExecInfo]; GO
4.3. Les vues des déclencheurs sont créées de la même manière (si nécessaire). Quant à moi, je n'ai pas besoin de déclencheurs de traçage, car s'il y a des problèmes avec les déclencheurs, l'exécution des procédures stockées et des requêtes les affichera.
Les deux paramètres suivants ont une importance vitale pour les vues implémentées :
- AvgWorkerSec :temps d'exécution de la requête en secondes.
- AvgElapsedSec :temps d'attente ou temps d'attente + AvgWorkerSec.
En ce qui concerne les résultats des vues, l'égalité suivante est importante :
AvgWorkerSec=AvgElapsedSec
- AvgWorkerSec>AvgElapsedSec :ici, quelque chose charge fortement le processeur au moment de l'exécution de la requête (il s'est avéré que l'analyse du logiciel antivirus était en cours d'exécution ; cela peut également être la faute de la mise en parallèle du plan).
- AvgWorkerSec
Si AvgWorkerSec=AvgElapsedSec est respecté, le long temps d'exécution est lié à la requête elle-même et à son temps d'exécution.
Qu'est-ce qu'un critère de la durée d'exécution d'une requête ?
Il n'y a pas de réponse absolue à cette question. Cela dépend de ce que fait une requête, où et comment elle est utilisée, etc.
J'ai l'évaluation suivante pour les requêtes ad hoc et les procédures stockées :
- Jusqu'à 0,5 :bon pour les procédures stockées, aucun problème (pas d'attente d'exécution).
- Jusqu'à 0,1 :bon pour les requêtes, aucun problème (pas d'attente d'exécution).
- 0.5 - 1.0 :mauvais pour les procédures stockées, il y a des problèmes (il n'y a pas d'attentes d'exécution visibles pour un utilisateur, mais elles existent toujours et nécessitent une solution).
- 0,1 — 0,5 — mauvais pour les requêtes, il y a des problèmes (il n'y a pas d'attentes d'exécution visibles pour un utilisateur, mais elles existent toujours et doivent être résolues).
- Plus de 1,0 :mauvais pour les procédures stockées, il y a des problèmes (il y a de fortes chances qu'il y ait des attentes visibles pour les utilisateurs, le problème nécessite une solution immédiate).
- Plus de 0,5 :mauvais pour les requêtes, il y a des problèmes (il y a de fortes chances qu'il y ait des attentes visibles pour les utilisateurs, le problème nécessite une solution immédiate).
En ce qui concerne les requêtes non ad hoc (téléchargement de données, chargement de données), l'évaluation ci-dessus est choisie sur une base individuelle. Habituellement, il dépasse massivement les évaluations pour les requêtes ad hoc et les procédures stockées.
Si tous les logiciels utilisent les procédures stockées, vous ne pouvez tracer que les procédures stockées, car le travail des requêtes affecte toujours le travail des procédures stockées. C'est pourquoi, arrêtons-nous sur l'analyse de l'exécution des procédures stockées.
Créons un système de collecte d'informations sur les procédures stockées les plus lourdes pour une analyse ultérieure et l'exécution d'autotrace, selon l'algorithme suivant :
1. Création d'une table pour stocker les informations :
USE [DATABASE_NAME] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [srv].[SQL_TopProcedureExecStat]( [Row_GUID] [uniqueidentifier] NOT NULL, [SERVER] [nvarchar](255) NOT NULL, [DB_ID] [int] NOT NULL, [OBJECT_ID] [int] NOT NULL, [ExecutionCount] [bigint] NOT NULL, [TotalWorkerTime] [bigint] NULL, [TotalElapsedTime] [bigint] NULL, [Func] [decimal](8, 2) NULL, [AvgWorkerSec] [decimal](8, 2) NULL, [AvgElapsedSec] [decimal](8, 2) NULL, [DB_NAME] [nvarchar](255) NULL, [SCHEMA_NAME] [nvarchar](255) NULL, [OBJECT_NAME] [nvarchar](255) NULL, [InsertUTCDate] [datetime] NOT NULL, [TotalPhysicalReads] [bigint] NULL, [TotalLogicalReads] [bigint] NULL, [TotalLogicalWrites] [bigint] NULL, [AvgPhysicalReads] [bigint] NULL, [AvgLogicalReads] [bigint] NULL, [AvgLogicalWrites] [bigint] NULL, [CategoryName] [nvarchar](255) NULL, CONSTRAINT [PK_SQL_TopProcedureExecStat] PRIMARY KEY CLUSTERED ( [Row_GUID] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] GO ALTER TABLE [srv].[SQL_TopProcedureExecStat] ADD CONSTRAINT [DF_SQL_TopProcedureExecStat_Row_GUID] DEFAULT (newid()) FOR [Row_GUID] GO ALTER TABLE [srv].[SQL_TopProcedureExecStat] ADD CONSTRAINT [DF_SQL_TopProcedureExecStat_SERVER] DEFAULT (@@servername) FOR [SERVER] GO ALTER TABLE [srv].[SQL_TopProcedureExecStat] ADD CONSTRAINT [DF_SQL_TopProcedureExecStat_InsertUTCDate] DEFAULT (getutcdate()) FOR [InsertUTCDate] GO
2. Création d'une procédure stockée de collecte d'informations :
USE [DATABASE_NAME] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE PROCEDURE [srv].[InsertTopProcedureExecStat] @top tinyint=24 – number of days to store records ,@CategoryName nvarchar(255)='AvgWorkerSec' – a category for selection AS BEGIN SET NOCOUNT ON; INSERT INTO [srv].[SQL_TopProcedureExecStat] ([DB_ID] ,[OBJECT_ID] ,[ExecutionCount] ,[TotalWorkerTime] ,[TotalElapsedTime] ,[AvgWorkerSec] ,[AvgElapsedSec] ,[DB_NAME] ,[SCHEMA_NAME] ,[OBJECT_NAME] ,InsertUTCDate ,CategoryName ,TotalPhysicalReads ,TotalLogicalReads ,TotalLogicalWrites ,AvgPhysicalReads ,AvgLogicalReads ,AvgLogicalWrites) select top(@top) [database_id] ,[object_id] ,[Num] ,[TotalWorkerTime] ,[TotalElapsedTime] ,[AvgWorkerSec] ,[AvgElapsedSec] ,[DB_NAME] ,[SCHEMA_NAME] ,[PROCEDURE_NAME] ,InsertUTCDate ,CategoryName ,TotalPhysicalReads ,TotalLogicalReads ,TotalLogicalWrites ,AvgPhysicalReads ,AvgLogicalReads ,AvgLogicalWrites from( select [database_id] ,[object_id] ,[Num] ,[TotalWorkerTime] ,[TotalElapsedTime] ,[AvgWorkerSec] ,[AvgElapsedSec] ,[DB_NAME] ,[SCHEMA_NAME] ,[PROCEDURE_NAME] ,getUTCDate() as InsertUTCDate ,@CategoryName as CategoryName ,TotalPhysicalReads ,TotalLogicalReads ,TotalLogicalWrites ,AvgPhysicalReads ,AvgLogicalReads ,AvgLogicalWrites FROM [srv].[vProcedureExecTotalInfoHour] ) as t order by case @CategoryName when 'TotalWorkerTime' then TotalWorkerTime when 'TotalElapsedTime' then TotalElapsedTime when 'AvgWorkerSec' then AvgWorkerSec when 'AvgElapsedSec' then AvgElapsedSec when 'TotalPhysicalReads' then TotalPhysicalReads when 'TotalLogicalReads' then TotalLogicalReads when 'TotalLogicalWrites' then TotalLogicalWrites when 'AvgPhysicalReads' then AvgPhysicalReads when 'AvgLogicalReads' then AvgLogicalReads when 'AvgLogicalWrites' then AvgLogicalWrites end desc; declare @count int=(select count(*) from [srv].[SQL_TopProcedureExecStat] where [email protected]); declare @diff [email protected]@top; ;with tbl_del as( select Row_GUID from [srv].[SQL_TopProcedureExecStat] where InsertUTCDate<DateAdd(hour,-24,getUTCDate()) and [email protected] ) delete from [srv].[SQL_TopProcedureExecStat] where Row_GUID in (select Row_GUID from tbl_del); --if table contains more records that it is specified in @top, the most insignificant records are deleted set @count = (select count(*) from [srv].[SQL_TopProcedureExecStat] where [email protected]) set @diff = @count - @Top - 3 if(@diff>0) begin ;with tbl_del as( select top(@diff) Row_GUID from [srv].[SQL_TopProcedureExecStat] where [email protected] order by case @CategoryName when 'TotalWorkerTime' then TotalWorkerTime when 'TotalElapsedTime' then TotalElapsedTime when 'AvgWorkerSec' then AvgWorkerSec when 'AvgElapsedSec' then AvgElapsedSec when 'TotalPhysicalReads' then TotalPhysicalReads when 'TotalLogicalReads' then TotalLogicalReads when 'TotalLogicalWrites' then TotalLogicalWrites when 'AvgPhysicalReads' then AvgPhysicalReads when 'AvgLogicalReads' then AvgLogicalReads when 'AvgLogicalWrites' then AvgLogicalWrites end ) delete from [srv].[SQL_TopProcedureExecStat] where Row_GUID in (select Row_GUID from tbl_del); end declare @DB_ID int declare @OBJECT_ID int declare @top1 int = 3 declare @diff1 int declare @count1 int -- deletion of more than @top1 times repeats of the specific procedure select top (1) @count1 = tp.num ,@DB_ID = tp.DB_ID ,@OBJECT_ID = tp.OBJECT_ID from (select count(*) as num, DB_ID, OBJECT_ID from [srv].[SQL_TopProcedureExecStat] where [email protected] group by DB_ID, OBJECT_ID) as tp order by tp.num desc; set @diff1 = @count1 - @top1; if(@diff1) > 0 begin ;with tbl_del as( select top(@diff1) Row_GUID from [srv].[SQL_TopProcedureExecStat] where DB_ID = @DB_ID and OBJECT_ID = @OBJECT_ID and [email protected] order by case @CategoryName when 'TotalWorkerTime' then TotalWorkerTime when 'TotalElapsedTime' then TotalElapsedTime when 'AvgWorkerSec' then AvgWorkerSec when 'AvgElapsedSec' then AvgElapsedSec when 'TotalPhysicalReads' then TotalPhysicalReads when 'TotalLogicalReads' then TotalLogicalReads when 'TotalLogicalWrites' then TotalLogicalWrites when 'AvgPhysicalReads' then AvgPhysicalReads when 'AvgLogicalReads' then AvgLogicalReads when 'AvgLogicalWrites' then AvgLogicalWrites end ) delete from [srv].[SQL_TopProcedureExecStat] where Row_GUID in (select Row_GUID from tbl_del); end -- deletion of more than 1 repeats of the AvgWorkerSec parameter for the specific procedure if @CategoryName = 'AvgWorkerSec' begin declare @AvgWorkerSec decimal(8,2) select top (1) @count1 = tp.num ,@DB_ID = tp.DB_ID ,@OBJECT_ID = tp.OBJECT_ID ,@AvgWorkerSec = tp.AvgWorkerSec from (select count(*) as num, DB_ID, OBJECT_ID, AvgWorkerSec from [srv].[SQL_TopProcedureExecStat] where [email protected] group by DB_ID, OBJECT_ID,AvgWorkerSec) as tp order by tp.num desc; set @diff1 = @count1 - 1; if(@diff1) > 0 begin ;with tbl_del as( select top(@diff1) Row_GUID from [srv].[SQL_TopProcedureExecStat] where DB_ID = @DB_ID and OBJECT_ID = @OBJECT_ID and [email protected] and AvgWorkerSec = @AvgWorkerSec order by InsertUTCDate desc ) delete from [srv].[SQL_TopProcedureExecStat] where Row_GUID in (select Row_GUID from tbl_del); end end if @CategoryName = 'AvgElapsedSec' begin declare @AvgElapsedSec decimal(8,2) select top (1) @count1 = tp.num ,@DB_ID = tp.DB_ID ,@OBJECT_ID = tp.OBJECT_ID ,@AvgElapsedSec = tp.AvgElapsedSec from (select count(*) as num, DB_ID, OBJECT_ID, AvgElapsedSec from [srv].[SQL_TopProcedureExecStat] where [email protected] group by DB_ID, OBJECT_ID,AvgElapsedSec) as tp order by tp.num desc; set @diff1 = @count1 - 1; if(@diff1) > 0 begin ;with tbl_del as( select top(@diff1) Row_GUID from [srv].[SQL_TopProcedureExecStat] where DB_ID = @DB_ID and OBJECT_ID = @OBJECT_ID and [email protected] and AvgElapsedSec = @AvgElapsedSec order by InsertUTCDate desc ) delete from [srv].[SQL_TopProcedureExecStat] where Row_GUID in (select Row_GUID from tbl_del); end end END GO
It is better to run this stored procedure immediately after collecting information about the stored procedures (we can set up a task in Agent for running it every 5-10 minutes for queries, stored procedures and triggers):
exec [srv].[InsertForSQL_StatementExecStat]; --collecting information about executed queries exec [srv].[InsertForTriggerExecStat]; --collecting information about executed triggers exec [srv].[InsertForProcedureExecStat]; --collecting information about executed stored procedures --collecting information about the most heavy executed stored procedures, according to the criteria exec [srv].[InsertTopProcedureExecStat] @[email protected], @CategoryName='AvgWorkerSec'; exec [srv].[InsertTopProcedureExecStat] @[email protected], @CategoryName='AvgElapsedSec'
3. Running trace (every 5-10 minutes with the help of the Agent tasks, preferably right after collecting information):
USE [DATABASE_NAME]; go --coefficient of transition value of indicator declare @koef_red numeric(8,3)=1.3; --if there are records with the indicator greater than or equal to the --preset indicator coefficient if(exists( SELECT top(1) 1 FROM [srv].[SQL_TopProcedureExecStat] where CategoryName='AvgElapsedSec' or CategoryName='AvgWorkerSec' group by CategoryName having avg([AvgElapsedSec])>[email protected]_red or avg([AvgWorkerSec])>[email protected]_red)) begin --running autorace exec .[srv].[AutoTrace]; end
The auto-trace stored procedure is implemented on an individual basis. Par exemple :
USE [DATABASE_NAME] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE PROCEDURE [srv].[AutoTrace] @maxfilesize bigint=200 --maximum file size in Mb ,@run_minutes int=60 --tracing length in minutes ,@file_patch nvarchar(255)=N'Path to directory' --directory for trace file ,@file_name nvarchar(255)=N'Profiler' --file name ,@res_msg nvarchar(255)=NULL output --result in the form of messages AS BEGIN SET NOCOUNT ON; declare @rc int; declare @TraceID int; if(@run_minutes>=1200) set @run_minutes=1200; --no longer than 20 hours! declare @finish_dt datetime=DateAdd(minute,@run_minutes,GetDate()); --execution end time --end of trace file declare @finish_dt_inc nvarchar(255)=N'_'+cast(YEAR(@finish_dt) as nvarchar(255))+'_'+cast(MONTH(@finish_dt) as nvarchar(255))+'_'+cast(DAY(@finish_dt) as nvarchar(255)); declare @File nvarchar(255)[email protected]@[email protected]_dt_inc; --full name of the trace file DECLARE @result bit; DECLARE @msgerrors nvarchar(255); DECLARE @oldDT datetime; --Getting the last date and time if(object_id('DATABASE_NAME.dbo.TraceTable')<>0) begin select @oldDT=max(StartTime) from DATABASE_NAME.dbo.TraceTable where StartTime is not null; end --select @oldDT; --If the last date and time is not specified or it is less than time of trace ending,trace is run. Otherwise, the trace was executed on this date. if(@oldDT is null or @oldDT<DATETIMEFROMPARTS(YEAR(@finish_dt), MONTH(@finish_dt), DAY(@finish_dt), 0, 0, 0, 0)) begin --creating trace exec @rc = sp_trace_create @[email protected] output, --Trace ID @Options=0, --tracing options (by default) @[email protected], --trace file destination @[email protected], --maximum size of the trace file (when reaching maximum size, trace stops) @[email protected]_dt--, --end data and time of trace [email protected]=2; --number of files, at which the previous files are deleted (that are not used in the given set of trace options) --if the trace is created without errors (code 0), we can set up and tun it if (@rc = 0) begin -- Setting event for trace declare @on bit set @on = 1 exec sp_trace_setevent @TraceID, 10, 1, @on exec sp_trace_setevent @TraceID, 10, 9, @on exec sp_trace_setevent @TraceID, 10, 2, @on exec sp_trace_setevent @TraceID, 10, 66, @on exec sp_trace_setevent @TraceID, 10, 10, @on exec sp_trace_setevent @TraceID, 10, 3, @on exec sp_trace_setevent @TraceID, 10, 4, @on exec sp_trace_setevent @TraceID, 10, 6, @on exec sp_trace_setevent @TraceID, 10, 7, @on exec sp_trace_setevent @TraceID, 10, 8, @on exec sp_trace_setevent @TraceID, 10, 11, @on exec sp_trace_setevent @TraceID, 10, 12, @on exec sp_trace_setevent @TraceID, 10, 13, @on exec sp_trace_setevent @TraceID, 10, 14, @on exec sp_trace_setevent @TraceID, 10, 15, @on exec sp_trace_setevent @TraceID, 10, 16, @on exec sp_trace_setevent @TraceID, 10, 17, @on exec sp_trace_setevent @TraceID, 10, 18, @on exec sp_trace_setevent @TraceID, 10, 25, @on exec sp_trace_setevent @TraceID, 10, 26, @on exec sp_trace_setevent @TraceID, 10, 31, @on exec sp_trace_setevent @TraceID, 10, 34, @on exec sp_trace_setevent @TraceID, 10, 35, @on exec sp_trace_setevent @TraceID, 10, 41, @on exec sp_trace_setevent @TraceID, 10, 48, @on exec sp_trace_setevent @TraceID, 10, 49, @on exec sp_trace_setevent @TraceID, 10, 50, @on exec sp_trace_setevent @TraceID, 10, 51, @on exec sp_trace_setevent @TraceID, 10, 60, @on exec sp_trace_setevent @TraceID, 10, 64, @on exec sp_trace_setevent @TraceID, 12, 1, @on exec sp_trace_setevent @TraceID, 12, 9, @on exec sp_trace_setevent @TraceID, 12, 3, @on exec sp_trace_setevent @TraceID, 12, 11, @on exec sp_trace_setevent @TraceID, 12, 4, @on exec sp_trace_setevent @TraceID, 12, 6, @on exec sp_trace_setevent @TraceID, 12, 7, @on exec sp_trace_setevent @TraceID, 12, 8, @on exec sp_trace_setevent @TraceID, 12, 10, @on exec sp_trace_setevent @TraceID, 12, 12, @on exec sp_trace_setevent @TraceID, 12, 13, @on exec sp_trace_setevent @TraceID, 12, 14, @on exec sp_trace_setevent @TraceID, 12, 15, @on exec sp_trace_setevent @TraceID, 12, 16, @on exec sp_trace_setevent @TraceID, 12, 17, @on exec sp_trace_setevent @TraceID, 12, 18, @on exec sp_trace_setevent @TraceID, 12, 26, @on exec sp_trace_setevent @TraceID, 12, 31, @on exec sp_trace_setevent @TraceID, 12, 35, @on exec sp_trace_setevent @TraceID, 12, 41, @on exec sp_trace_setevent @TraceID, 12, 48, @on exec sp_trace_setevent @TraceID, 12, 49, @on exec sp_trace_setevent @TraceID, 12, 50, @on exec sp_trace_setevent @TraceID, 12, 51, @on exec sp_trace_setevent @TraceID, 12, 60, @on exec sp_trace_setevent @TraceID, 12, 64, @on exec sp_trace_setevent @TraceID, 12, 66, @on exec sp_trace_setevent @TraceID, 13, 1, @on exec sp_trace_setevent @TraceID, 13, 9, @on exec sp_trace_setevent @TraceID, 13, 3, @on exec sp_trace_setevent @TraceID, 13, 11, @on exec sp_trace_setevent @TraceID, 13, 4, @on exec sp_trace_setevent @TraceID, 13, 6, @on exec sp_trace_setevent @TraceID, 13, 7, @on exec sp_trace_setevent @TraceID, 13, 8, @on exec sp_trace_setevent @TraceID, 13, 10, @on exec sp_trace_setevent @TraceID, 13, 12, @on exec sp_trace_setevent @TraceID, 13, 14, @on exec sp_trace_setevent @TraceID, 13, 26, @on exec sp_trace_setevent @TraceID, 13, 35, @on exec sp_trace_setevent @TraceID, 13, 41, @on exec sp_trace_setevent @TraceID, 13, 49, @on exec sp_trace_setevent @TraceID, 13, 50, @on exec sp_trace_setevent @TraceID, 13, 51, @on exec sp_trace_setevent @TraceID, 13, 60, @on exec sp_trace_setevent @TraceID, 13, 64, @on exec sp_trace_setevent @TraceID, 13, 66, @on -- Setting filters declare @intfilter int; declare @bigintfilter bigint; exec sp_trace_setfilter @TraceID, 10, 0, 7, N'Application SQL Server Profiler - fa35966e-e426-4d1a-8753-8f971cf89495'; exec sp_trace_setfilter @TraceID, 35, 0, 6, N'%DATABASE_NAME%'; exec sp_trace_setfilter @TraceID, 35, 1, 6, N'%DATABASE_NAME%'; --Running trace exec sp_trace_setstatus @TraceID, 1; --setting execution time wait declare @run_delay [email protected]_minutes+1; --increase of wait for 1 minute from the preset trace execution time declare @run_delay_hour [email protected]_delay/60; --calculation of wait hours declare @run_delay_minute [email protected]_delay-(@run_delay/60)*60; --calculation of the remaining minutes declare @run_delay_hour_str nvarchar(2); --string representation of hours declare @run_delay_minute_str nvarchar(2); --string representation of minutes --adding missing nulls for string representation of hours if(@run_delay_hour=0) set @run_delay_hour_str='00'; else if(@run_delay_hour<10) set @run_delay_hour_str='0'+cast(@run_delay_hour as nvarchar(255)); else if(@run_delay_hour>=10) set @run_delay_hour_str=cast(@run_delay_hour as nvarchar(255)); --select @run_delay_hour, @run_delay_hour_str; --adding missing nulls for string representation of minutes if(@run_delay_minute=0) set @run_delay_minute_str='00'; else if(@run_delay_minute<10) set @run_delay_minute_str='0'+cast(@run_delay_minute as nvarchar(255)); else if(@run_delay_minute>=10) set @run_delay_minute_str=cast(@run_delay_minute as nvarchar(255)); --select @run_delay_minute, @run_delay_minute_str; --the hours:minutes string representation for the wait declare @run_delay_str nvarchar(255)[email protected]_delay_hour_str+':'[email protected]_delay_minute_str; --wait WAITFOR DELAY @run_delay_str; --select @run_delay_str; --deletion of the trace table, if it exists if(object_id('DATABASE_NAME.dbo.TraceTable')<>0) begin drop table DATABASE_NAME.dbo.TraceTable; end --creation and filling of the trace table from the trace file SELECT * INTO DATABASE_NAME.dbo.TraceTable FROM ::fn_trace_gettable(@File+'.trc', default); --adding extension to the full file set @[email protected]+'.trc'; --here, we need to insert code to delete the trace file declare @str_title nvarchar(max)='There was auto trace on the server'[email protected]@servername, @str_pred_mess nvarchar(max)='На '[email protected]@servername+'The auto trace has been run on the server. You can view the result in the Database_Name.dbo.TraceTable table; --here, we can send the auto trace run notification to administrator end --returning the result set @res_msg=N'ErrorCode='+cast(@rc as nvarchar(255))+'\r\n'+coalesce(@msgerrors, ''); end END GO
For more information on setting trace, refer to How to:Create a Trace (Transact-SQL).
Conclusion
In this article, we considered an example of implementation of a system for collecting information about the state of a database, that does not load the system. In case of problem detection, this system runs the preset trace and saves results into a table. This approach can be extended to several servers. In this case, we need to collect information from all servers for subsequent sending of information to administrators.
It is also important to remember about deletion of old data from the used tables. It is quite sufficient to store data within a month or two weeks.
Also read:
Implementing a Common MS SQL Server Performance Indicator
Références
- sys.dm_exec_trigger_stats
- sys.dm_exec_procedure_stats
- sys.dm_exec_query_stats
- sys.dm_exec_sql_text
- How to:Create a Trace (Transact-SQL)