Subject RE: [firebird-support] Optimization help: is null and not null?
Author Leyne, Sean
> You might want to add indices on the columns STATUS,
> HANDLED_TIMESTAMP and RECEIPT_TIMESTAMP

An index on HANDLED_TIMESTAMP will not help, in this case since indexes are never used in resolving IS NOT NULL conditions.

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