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When Should One Rebuild An Index? |
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Answer» You can run the 'ANALYZE INDEX VALIDATE STRUCTURE' command on the affected indexes - each invocation of this command creates a single row in the INDEX_STATS view. This row is OVERWRITTEN by the next ANALYZE INDEX command, so COPY the contents of the view into a local table after each ANALYZE. The 'badness' of the index can then be JUDGED by the ratio of 'DEL_LF_ROWS' to 'LF_ROWS'. You can run the 'ANALYZE INDEX VALIDATE STRUCTURE' command on the affected indexes - each invocation of this command creates a single row in the INDEX_STATS view. This row is overwritten by the next ANALYZE INDEX command, so copy the contents of the view into a local table after each ANALYZE. The 'badness' of the index can then be judged by the ratio of 'DEL_LF_ROWS' to 'LF_ROWS'. |
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