Re: pgsql: Support partition pruning at execution time

On 8 April 2018 at 10:59, David Rowley <david.rowley@2ndquadrant.com> wrote:
> Sometimes I see:
>
>  relname | relallvisible
> ---------+---------------
>  tprt_1  |             0
>  tprt_2  |             1
>
> Other times I see:
>
>  relname | relallvisible
> ---------+---------------
>  tprt_1  |             0
>  tprt_2  |             0

The minimum set of commands I can find to recreate this are:

drop table if exists tprt;
create table tprt (col1 int) partition by range (col1);
create table tprt_1 partition of tprt for values from (1) to (5001);
create index tprt1_idx on tprt_1 (col1);
insert into tprt values (10), (20), (501), (502), (505), (1001), (4500);
vacuum tprt; select relname,relallvisible from pg_Class where relname
like 'tprt%' and relkind = 'r';

I get relallvisible = 0 once in maybe 20 or so attempts.

I didn't manage to get the same without a partitioned table.

-- 
 David Rowley                   http://www.2ndQuadrant.com/
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