To periodically check the density of indexes for a table, run the sa_index_density system procedure. Density values range between 0 and 1. Values closer to 1 indicate little index fragmentation. Values less than 0.5, indicate a level of index fragmentation that may impact performance.
In Interactive SQL, run the following SQL statement to view the index fragmentation introduced to the fragment table during this tutorial:
CALL sa_index_density( 'fragment' ); |
TableName | TableId | IndexName | IndexId | IndexType | LeafPages | Density |
---|---|---|---|---|---|---|
fragment | 736 | idx_fragment | 1 | NUI | 1,177 | 0.597509 |
Your results might be different, but the Density column value should be approximately 0.6.
In Interactive SQL, run the following SQL statement to improve the density of the index:
ALTER INDEX idx_fragment ON fragment REBUILD; |
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