Marc Mamin wrote: > Hello, > > - did you vacuum your tables recently ? > > - What I miss in your query is a check for the rows that do not need > to be udated: > > AND NOT (service = b.service > AND status = b.status > AND has_notification = gateway_id NOT IN (4,101,102) > AND operator = COALESCE( b.actual_target_network_id, > b.requested_target_network_id ) > > > depending on the fraction of rows that are already up to date, the > might fasten your process quite a lot... I don't see why it would. As far as I know, the high saving in update time is done by using the indices. All the other conditions that are not on indices are all checked using a sequential scan on the rows that were brought from the index, so adding more conditions wouldn't make this a lot faster - maybe even slower because more comparisons are made.
In any case, the logic of the database is that the records that have delivered = 0 are always a subset of the records that are changed in this query, so querying on delivered=0 - which is an indexed query - actually make the above redundant. Thanks for your response, Herouth
