On Fri, Sep 29, 2017 at 1:32 PM, Victor Yegorov <vyegorov@xxxxxxxxx> wrote:
Greetings.I am looking into new partitioning of 10rc1 on a copy of a production system.And I'm having tough times with the full scan.Per documentation:> It is possible to avoid this scan by adding a valid CHECK constraint to the table> that would allow only the rows satisfying the desired partition constraint before> running this command. It will be determined using such a constraint that the table> need not be scanned to validate the partition constraint.So I have this table with CHECK constraint:test=# \d stats_201503Table "public.stats_201503"Column Type Collation Nullable Default---------------------------- --------------------------- --------- -------- ------------------------------------------------ …created_at timestamp without time zone…Check constraints:"stats_201503_created_at_check" CHECK (created_at >= '2015-02-28 19:00:00'::timestamp without time zone AND created_at < '2015-03-31 20:00:00'::timestamp without time zone) Still, if I try to attach it, I get Full Scan:test=# ALTER TABLE jsm ATTACH PARTITION stats_201503 FOR VALUES FROM ('2015-02-28 19:00:00') TO ('2015-03-31 20:00:00');ALTER TABLETime: 55502.875 ms (00:55.503)Is it possible to avoid Full Scan here? I have TBs worth of data in partitions,so it'll takes ages to switch to the declarative partitioning the way things stand now.Thanks in advance.--Victor Yegorov
>Is it possible to avoid Full Scan here?
Have you verified that constraint_exclusion is set to "on" or "partition" ?
