1. To re-index/rebuild fragmented indexes in your database run the following script on each of your databases. Note: It will REORGANISE indexes lower than 30 and REBUILD all indexes above 30
SELECT dbschemas.[name] as 'Schema',
dbtables.[name] as 'Table',
dbindexes.[name] as 'Index',
indexstats.alloc_unit_type_desc,
indexstats.avg_fragmentation_in_percent,
indexstats.page_count,
CASE WHEN indexstats.avg_fragmentation_in_percent > 30 THEN
'ALTER INDEX [' + dbindexes.[name] + '] ON ' + dbschemas.[name] + '.' + dbtables.[name] + ' REBUILD'
WHEN indexstats.avg_fragmentation_in_percent >= 15 AND indexstats.avg_fragmentation_in_percent <= 30 THEN
'ALTER INDEX [' + dbindexes.[name] + '] ON ' + dbschemas.[name] + '.' + dbtables.[name] + ' REORGANIZE'
END
FROM sys.dm_db_index_physical_stats (DB_ID(), NULL, NULL, NULL, NULL) AS indexstats
INNER JOIN sys.tables dbtables on dbtables.[object_id] = indexstats.[object_id]
INNER JOIN sys.schemas dbschemas on dbtables.[schema_id] = dbschemas.[schema_id]
INNER JOIN sys.indexes AS dbindexes ON dbindexes.[object_id] = indexstats.[object_id]
AND indexstats.index_id = dbindexes.index_id
WHERE indexstats.database_id = DB_ID()
ORDER BY indexstats.avg_fragmentation_in_percent desc
GO
DECLARE @NoOfPartitions BIGINT;
DECLARE @objectid INT;
DECLARE @indexid INT;
DECLARE @idxname NVARCHAR(255);
DECLARE @objname NVARCHAR(255);
DECLARE @partitionnum BIGINT;
DECLARE @schemaname NVARCHAR(255);
DECLARE @partitions BIGINT;
DECLARE @frag FLOAT;
DECLARE @statement VARCHAR(8000);
-- checking existance of the table that we create for temporary purpose
IF OBJECT_ID('defrag_work', 'U') IS NOT NULL
DROP TABLE defrag_work;
-- Copy the fragmented indexes data into defrag_work table
-- All the indexes that has fragmentation < 5 are getting stored into our work table
SELECT [object_id] AS objectid ,
index_id AS indexid ,
partition_number AS partition_no ,
avg_fragmentation_in_percent AS frag
INTO defrag_work
FROM sys.dm_db_index_physical_stats(DB_ID(), NULL, NULL, NULL, 'LIMITED')
WHERE avg_fragmentation_in_percent >5.0 and index_id > 0;
-- cursor to process the list of partitions
DECLARE partitions CURSOR
FOR
SELECT *
FROM defrag_work;
-- Open the cursor.
OPEN partitions;
-- Looping through the partitions
FETCH NEXT
FROM partitions
INTO @objectid, @indexid, @partitionnum, @frag;
WHILE @@FETCH_STATUS = 0
BEGIN;
SELECT @objname= QUOTENAME(so.name) ,
@schemaname = QUOTENAME(ss.name)
FROM sys.objects AS so
JOIN sys.schemas AS ss ON ss.schema_id = so.schema_id
WHERE so.object_id = @objectid;
SELECT @idxname = QUOTENAME(name)
FROM sys.indexes
WHERE object_id = @objectid
AND index_id = @indexid;
SELECT @NoOfPartitions = COUNT(*)
FROM sys.partitions
WHERE object_id = @objectid
AND index_id = @indexid;
/*
Let’s say N = fragmentation percentage
N <= 5 = IGNORE
5 < N < 30 = REORGANIZE
N > 30 = REBUILD
*/
IF (@frag < 30.0) -- @frag > 5 is already filtered in our first query, so we need that condition here
BEGIN;
SELECT @statement = 'ALTER INDEX ' + @idxname + ' ON '
+ @schemaname + '.' + @objname + ' REORGANIZE';
IF @NoOfPartitions > 1
SELECT @statement = @statement + ' PARTITION='
+ CONVERT (CHAR, @partitionnum);
PRINT @statement;
--EXEC (@statement);
END;
IF @frag >= 30.0
BEGIN;
SELECT @statement = 'ALTER INDEX ' + @idxname + ' ON '
+ @schemaname + '.' + @objname + ' REBUILD';
IF @NoOfPartitions > 1
SELECT @statement = @statement + ' PARTITION='
+ CONVERT (CHAR, @partitionnum);
PRINT @statement;
--EXEC (@statement);
END;
--PRINT 'Executed ' + @statement;
FETCH NEXT FROM partitions INTO @objectid, @indexid, @partitionnum,
@frag;
END;
-- Close and deallocate the cursor.
CLOSE partitions;
DEALLOCATE partitions;
-- drop the table
IF OBJECT_ID('defrag_work', 'U') IS NOT NULL
DROP TABLE defrag_work;
Note: This script will display 7 columns, you need to copy all the rows in the last column and run those now in the same database, it will look something like:
ALTER INDEX [PK_Document_Note] ON Document.Document_Note REBUILD