Como automatizar a manutenção de índice
Atualizado em: 2009-04-30
O script a seguir verifica todos os índices em um banco de dados do Planning Server e localiza aqueles que têm uma média de fragmentação superior a 10%. Em seguida, dependendo do grau de fragmentação, ele executa a reorganização ou a reconstrução desses índices.
Exemplo
Exemplo de consulta
-- ensure a USE <databasename> statement has been executed first.
SET NOCOUNT ON;
DECLARE @objectid int;
DECLARE @indexid int;
DECLARE @partitioncount bigint;
DECLARE @schemaname sysname;
DECLARE @objectname sysname;
DECLARE @indexname sysname;
DECLARE @partitionnum bigint;
DECLARE @partitions bigint;
DECLARE @frag float;
DECLARE @command varchar(8000);
-- ensure the temporary table does not exist
IF EXISTS (SELECT name FROM sys.objects WHERE name = 'work_to_do')
DROP TABLE work_to_do;
-- conditionally select from the function, converting object and index IDs to names.
SELECT
object_id AS objectid,
index_id AS indexid,
partition_number AS partitionnum,
avg_fragmentation_in_percent AS frag
INTO work_to_do
FROM sys.dm_db_index_physical_stats (DB_ID(), NULL, NULL , NULL, 'LIMITED')
WHERE avg_fragmentation_in_percent > 10.0 AND index_id > 0;
-- Declare the cursor for the list of partitions to be processed.
DECLARE partitions CURSOR FOR SELECT * FROM work_to_do;
-- Open the cursor.
OPEN partitions;
-- Loop through the partitions.
FETCH NEXT
FROM partitions
INTO @objectid, @indexid, @partitionnum, @frag;
WHILE @@FETCH_STATUS = 0
BEGIN;
SELECT @objectname = o.name, @schemaname = s.name
FROM sys.objects AS o
JOIN sys.schemas as s ON s.schema_id = o.schema_id
WHERE o.object_id = @objectid;
SELECT @indexname = name
FROM sys.indexes
WHERE object_id = @objectid AND index_id = @indexid;
SELECT @partitioncount = count (*)
FROM sys.partitions
WHERE object_id = @objectid AND index_id = @indexid;
-- 30 is an arbitrary decision point at which to switch between reorganizing and rebuilding
IF @frag < 30.0
BEGIN;
SELECT @command = 'ALTER INDEX [' + @indexname + '] ON ' + @schemaname + '.[' + @objectname + '] REORGANIZE';
IF @partitioncount > 1
SELECT @command = @command + ' PARTITION=' + CONVERT (CHAR, @partitionnum);
EXEC (@command);
END;
IF @frag >= 30.0
BEGIN;
SELECT @command = 'ALTER INDEX [' + @indexname +'] ON ' + @schemaname + '.[' + @objectname + '] REBUILD';
IF @partitioncount > 1
SELECT @command = @command + ' PARTITION=' + CONVERT (CHAR, @partitionnum);
EXEC (@command);
END;
PRINT 'Executed ' + @command;
FETCH NEXT FROM partitions INTO @objectid, @indexid, @partitionnum, @frag;
END;
-- Close and deallocate the cursor.
CLOSE partitions;
DEALLOCATE partitions;
-- drop the temporary table
IF EXISTS (SELECT name FROM sys.objects WHERE name = 'work_to_do')
DROP TABLE work_to_do;
GO
Exemplos de resultados
Os resultados a seguir são os exemplos da execução desta consulta em um banco de dados de aplicativo do Planning Server.
Executed ALTER INDEX XPKAsyncWorkItems ON dbo.AsyncWorkItems REBUILD
Executed ALTER INDEX XPKAsyncWorkItemStatusHistory ON dbo.AsyncWorkItemStatusHistory REBUILD
Executed ALTER INDEX XPKWorkbooks ON dbo.Workbooks REBUILD
Executed ALTER INDEX XPKRecurrentCycles ON dbo.RecurrentCycles REBUILD
Executed ALTER INDEX XPKCycleInstances ON dbo.CycleInstances REBUILD
Executed ALTER INDEX XPKAG_AccountType ON dbo.AG_AccountType REBUILD
Executed ALTER INDEX XPKAssignmentDefinitions ON dbo.AssignmentDefinitions REBUILD
Executed ALTER INDEX XPKD_Account ON dbo.D_Account REBUILD
Executed ALTER INDEX XD_Account_Label_U ON dbo.D_Account REBUILD
Executed ALTER INDEX XPKAssignments ON dbo.Assignments REBUILD
Executed ALTER INDEX MG_ConsolidationModel_MeasureGroup_default_partition_PK ON dbo.MG_ConsolidationModel_MeasureGroup_default_partition REBUILD
Executed ALTER INDEX H_Account_Consolidation_PK ON dbo.H_Account_Consolidation REBUILD
Executed ALTER INDEX D_Product_PK ON dbo.D_Product REBUILD
Executed ALTER INDEX H_Product_ResortProducts_PK ON dbo.H_Product_ResortProducts REBUILD
Executed ALTER INDEX MG_Corporate Costs_MeasureGroup_default_partition_PK ON dbo.MG_Corporate Costs_MeasureGroup_default_partition REORGANIZE
Executed ALTER INDEX XPKRuleSetsOrRules ON dbo.RuleSetsOrRules REBUILD
Executed ALTER INDEX RuleSetsOrRules_GUID_U ON dbo.RuleSetsOrRules REBUILD
Executed ALTER INDEX RuleSetsOrRules_Label_U ON dbo.RuleSetsOrRules REBUILD
Executed ALTER INDEX XPKRuleSets_Rules_Assoc ON dbo.RuleSets_Rules_Assoc REBUILD
Executed ALTER INDEX XPKBizRoles ON dbo.BizRoles REBUILD
Executed ALTER INDEX H_HR_HR_PK ON dbo.H_HR_HR REORGANIZE
Executed ALTER INDEX XPKBizDataPermissions ON dbo.BizDataPermissions REBUILD
O administrador do banco de dados pode personalizar o script anterior para reconstruir ou reorganizar índices diferentes em freqüências diferentes. Por exemplo, você pode modificar o script para reconstruir ou reorganizar índices de cluster nas tabelas do grupo de medidas diariamente e outros índices semanalmente.