Index to be recreated in Sql Server

When your database grows, the index fragmentation becomes too high,that will scale down the performance of the sql server. To overcome that we need to re-build the index, that should be done at the down time of the server.Here there is a query that will list all the index to be recreated/rebuild.It uses the following tables(sys.indexes,sys.tables,sys.schemas,sys.dm_db_index_physical_stats,sys.partitions). For detailed checkup change the last NULL in the dm_db_index_physical_stats call to 'SAMPLED' or even 'DETAILED'

SELECT 'ALTER INDEX [' + ix.name + '] ON [' + s.name + '].[' + t.name +'] ' +
CASE WHEN ps.avg_fragmentation_in_percent > 40 THEN 'REBUILD'
ELSE 'REORGANIZE' END +
CASE WHEN pc.partition_count > 1 THEN ' PARTITION = ' +
cast(ps.partition_number as nvarchar(max)) ELSE '' END
FROM sys.indexes AS ix INNER JOIN sys.tables t
ON t.object_id = ix.object_id
INNER JOIN sys.schemas s
ON t.schema_id = s.schema_id
INNER JOIN (SELECT object_id, index_id,avg_fragmentation_in_percent, partition_number
FROM sys.dm_db_index_physical_stats (DB_ID(), NULL,NULL, NULL, NULL)) ps
ON t.object_id = ps.object_id AND ix.index_id = ps.index_id
INNER JOIN (SELECT object_id, index_id, COUNT(DISTINCT
partition_number) AS partition_count
FROM sys.partitions
GROUP BY object_id, index_id) pc
ON t.object_id = pc.object_id AND ix.index_id = pc.index_id
WHERE ps.avg_fragmentation_in_percent > 10 AND
ix.name IS NOT NULL