On 2014-09-03 09:31:50 -0400, Robert Haas wrote:
> On Fri, Aug 29, 2014 at 1:26 PM, Andres Freund <andres@2ndquadrant.com> wrote:
> > We have pg_get_serial_sequence() mapping (relation, colum) to the
> > sequence. What I'm missing right now is the inverse. I.e. given a
> > sequence tell me the owner.
> > describe.c has a query for that, and it's not too hard to write, but it
> > still seems 'unfriendly' not to provide it.
> >
> > Does anybody dislike adding a function for that?
>
> I'll go out on a limb and say that it sounds like pointless catalog
> bloat to me. I am all in favor of adding things like this where the
> SQL query is painful to write (e.g. things involving pg_depend) but if
> it's a simple SELECT query then, eh, not really excited about it.
There's not really a simple select for it, is there? psql uses:
/* Get the column that owns this sequence */ printfPQExpBuffer(&buf, "SELECT pg_catalog.quote_ident(nspname) ||
'.'||" "\n pg_catalog.quote_ident(relname) || '.' ||" "\n
pg_catalog.quote_ident(attname)" "\nFROM pg_catalog.pg_class c" "\nINNER JOIN
pg_catalog.pg_dependd ON c.oid=d.refobjid" "\nINNER JOIN pg_catalog.pg_namespace n ON n.oid=c.relnamespace"
"\nINNER JOIN pg_catalog.pg_attribute a ON (" "\n a.attrelid=c.oid AND"
"\n a.attnum=d.refobjsubid)" "\nWHERE d.classid='pg_catalog.pg_class'::pg_catalog.regclass"
"\nAND d.refclassid='pg_catalog.pg_class'::pg_catalog.regclass" "\n AND d.objid=%s"
"\n AND d.deptype='a'", oid);
Greetings,
Andres Freund
-- Andres Freund http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services
