How to create a custom index.

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• IT Management Suite

Issue/Introduction

 

Resolution

Understanding and implementing a custom index on a heavily read CMDB table can greatly improve product performance. This performance gain has a tradeoff. SQL queries using the indexed field will resolve much quicker than a non-indexed field. There are a few ways of determining potential new index. Here is one SQL statement method for determining the tables and fields that have taken the longest for a SQL server to return results:

 

SELECT top 10 reverse(substring(reverse([statement]), 2, charindex('[',reverse([statement]))-2)) [Table],

                ROUND(avg_total_user_cost * avg_user_impact * (user_seeks + user_scans),0) [Total User Cost],

                mid.equality_columns [Equality Columns],

                mid.inequality_columns [Inequality Columns],

                mid.included_columns [Included Columns]         

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 mid.index_handle = mig.index_handle

ORDER BY [Total User Cost] DESC

 

To create the new indexes, please consult Microsoft SQL Server documentation or follow this link: 

http://msdn.microsoft.com/en-us/library/ms188783.aspx

 

*Symantec support does not support, diagnos, or assist in the creation of custom indexes, but when implemented correctly, custom indexes have great benefits.