Re: Internal function returning pg_statistic

Hi

st 20. 11. 2019 v 10:59 odesílatel Konstantin Knizhnik <
k(dot)knizhnik(at)postgrespro(dot)ru> napsal:

> Hi hackers,
>
> Working on global temporary table I need to define function which
> returns set of pg_statistic records.
> Unfortunately I failed to declare such function!
> Type pg_statistic is defined in postgres.bki so I was not able to refer
> to it in pg_proc.dat file.
> And if I explicitly enumerate columns of this type:
>
>
you can define your function in postgres.bki.

it will not be first

Pavel

> { oid => '3434',
> descr => 'show local statistics for global temp table',
> proname => 'pg_gtt_statistic_for_relation', provolatile => 'v',
> proparallel => 'u',
> prorettype => 'record', proretset => 't', proargtypes => 'oid',
> proallargtypes =>
>
> '{oid,oid,int2,bool,float4,int4,float4,int2,int2,int2,int2,int2,oid,oid,oid,oid,oid,oid,oid,oid,oid,oid,_float4,_float4,_float4,_float4,_float4,anyarray,anyarray,anyarray,anyarray,anyarray}',
> proargmodes =>
> '{i,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o}',
> proargnames =>
>
> '{relid,starelid,staattnum,stainherit,stanullfrac,stawidth,stadistinct,stakind1,stakind2,stakind3,stakind4,stakind5,staop1,staop2,staop3,staop4,staop5,stacoll1,stacoll2,stacoll3,stacoll4,stacoll5,stanumbers1,stanumbers2,stanumbers3,stanumbers4,stanumbers5,stavalues1,stavalues2,stavalues3,stavalues4,stavalues5}',
> prosrc => 'pg_gtt_statistic_for_relation' },
>
> then I go the following error when try to use this function:
>
> a column definition list is required for functions returning "record"
> at character 111
>
> The column definition list provided in pg_proc.dat was rejected because
> it contains reference to anyarray which can not be resolved.
>
> If I try to declare function in system_views.sql as returning setof
> pg_statistic then I got error "cannot change return type of existing
> function".
>
> CREATE OR REPLACE FUNCTION
> pg_gtt_statistic_for_relation(relid oid) returns setof pg_statistic
> LANGUAGE INTERNAL STRICT
> AS 'pg_gtt_statistic_by_relation';
>
> And if I try to declare it as returning record and explicitly cast it to
> pg_statistic, then reported error is "cannot cast type record to
> pg_statistic".
>
> So the only possible way I found is to create extension and define
> function in this extension.
> I wonder if there is some better solution?
>
> Thanks in advance,
>
> --
> Konstantin Knizhnik
> Postgres Professional: http://www.postgrespro.com
> The Russian Postgres Company
>
>
>
>