On 31 July 2018 at 11:25, Alvaro Herrera <alvhe...@2ndquadrant.com> wrote: > Not looking at the code right now either, but removing that assert and > then removing the TABLESAMPLE clause, the query returns identical > results with and without pruning, so maybe you're right. No time for > further looking now.
I thought about this a bit more and it seems fine just to remove the Assert. The patch that's pending in [1] adds all the correct handling for subplans that don't belong in any partition hierarchy. That's not the case for Jaime's plan, but those sub-partitioned tables will be identified just like any other partition by the run-time pruning code and can be pruned in the same way. The attached patch removes the Assert, but I think it should be probably be done as part of [1]'s patch since that's also adding the code to handle subplans for tables that don't belong in the partition hierarchy. I also spent a bit of time trying to create a simple test case for this and I've discovered that it's really not very easy and I have doubts about how stable such a plan might be. > (SELECT 'Jaime' <> 'Jamie' COLLATE es_EC) Apologies. It was a finger auto-pilot malfunction. [1] https://www.postgresql.org/message-id/CAKJS1f_eYwHk2x0xX7qW42rV_GRsJGBMe3AqN9MYLRSs1S%2BCiA%40mail.gmail.com -- David Rowley http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
remove_incorrect_partprune_assert.patch
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