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copied!<p>A view is a macro that is expanded into the outer query. Unless it's an indexed view and you have enterprise edition, it's simply ignored.</p> <p>So if you join 3 views and each views uses 5 tables, you have big join with 15 tables.</p> <p>You best bet is the <a href="http://msdn.microsoft.com/en-us/library/ms173494%28SQL.90%29.aspx" rel="nofollow noreferrer">Database Tuning Advisor</a> or a missing index script:</p> <pre><code>SELECT CONVERT(decimal(28, 1), migs.avg_total_user_cost * migs.avg_user_impact * (migs.user_seeks + migs.user_scans)) AS improvement_measure, 'CREATE INDEX missing_index_' + CONVERT(varchar, mig.index_group_handle) + '_' + CONVERT(varchar, mid.index_handle) + ' ON ' + mid.statement + ' (' + ISNULL(mid.equality_columns, '') + CASE WHEN mid.equality_columns IS NOT NULL AND mid.inequality_columns IS NOT NULL THEN ',' ELSE '' END + ISNULL(mid.inequality_columns, '') + ')' + ISNULL(' INCLUDE (' + mid.included_columns + ')', '') AS create_index_statement, migs.*, mid.database_id, mid.[object_id], mig.index_group_handle, mid.index_handle FROM sys.dm_db_missing_index_groups mig INNER JOIN sys.dm_db_missing_index_group_stats migs ON migs.group_handle = mig.index_group_handle INNER JOIN sys.dm_db_missing_index_details mid ON mig.index_handle = mid.index_handle WHERE CONVERT(decimal(28, 1), migs.avg_total_user_cost * migs.avg_user_impact * (migs.user_seeks + migs.user_scans)) > 10 AND database_id = DB_ID() ORDER BY migs.avg_total_user_cost * migs.avg_user_impact * (migs.user_seeks + migs.user_scans) DESC </code></pre> <p>Edit, after example</p> <p>You are nesting views on top of views. No optimisations are possible of the view itself. </p> <p>As mentioned, this can't be indexed</p>

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