Subject | RE: [firebird-support] Optimization help: is null and not null? |
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Author | Leyne, Sean |
Post date | 2014-04-01T13:29:27Z |
> You might want to add indices on the columns STATUS,An index on HANDLED_TIMESTAMP will not help, in this case since indexes are never used in resolving IS NOT NULL conditions.
> HANDLED_TIMESTAMP and RECEIPT_TIMESTAMP
Further, depending on the selectivity of values a compound index on STATUS + RECEIPT_TIMESTAMP (in that order) is likely to be better than separate indexes for the columns.
Sean