Re: [GENERAL] Temporary tables and miscellaneous schemas - Mailing list pgsql-patches

Sean Chittenden wrote:
> Hiding pg_temp_* schemas seems like a good idea to me given temp
> objects are visible in every schema and the path of a temp object is
> subject to change... an overly diligent admin might try and hard code
> in the schema of a temp object only to find that path not portable,
> thus exposing that information would strike me as a liability and not
> an asset.  And then there's the idea of providing an admin-mode that
> exposes all of the implementation details (Hint, hint.  I'd do the leg
> work on this if it wouldn't be categorically dropped at the front
> door).  Anyway, I know we've covered this in the archives so I'll drop
> it.
>
> As an FYI, I just updated to an Opteron box and have been enjoying a
> little over 1500 temp schemas and a paltry ~30 non-temp schemas.
> Getting this patch in would be oh so very appreciated as maintaining
> local copies of psql(1) is getting old.  I know it's not my decision
> to make, but I'd settle and shut up if there was an indirect proof for
> why this shouldn't be included as a patch (ie, a valid usecase for an
> admin or programmer who would need to see any or all of the pg_temp_*
> schemas without using that data to extract more bits from the
> pg_catalogs.  If they know how to go through the catalogs, why do they
> need \dn to display the temp schemas?).

OK, the following patch uses UNION and an =ANY() join to the
current_schemas() array to suppress non-local temp schemas, but display
all other schemas.

There is now cleaner way to join to the current_schemas() array, right?

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073
Index: src/bin/psql/describe.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/bin/psql/describe.c,v
retrieving revision 1.90
diff -c -c -r1.90 describe.c
*** src/bin/psql/describe.c    1 Dec 2003 22:21:54 -0000    1.90
--- src/bin/psql/describe.c    22 Dec 2003 06:58:48 -0000
***************
*** 1626,1639 ****

      initPQExpBuffer(&buf);
      printfPQExpBuffer(&buf,
!                       "SELECT n.nspname AS \"%s\",\n"
!                       "       u.usename AS \"%s\"\n"
          "FROM pg_catalog.pg_namespace n LEFT JOIN pg_catalog.pg_user u\n"
!                       "       ON n.nspowner=u.usesysid\n",
                        _("Name"),
                        _("Owner"));

!     processNamePattern(&buf, pattern, false, false,
                         NULL, "n.nspname", NULL,
                         NULL);

--- 1626,1650 ----

      initPQExpBuffer(&buf);
      printfPQExpBuffer(&buf,
!         "SELECT n.nspname AS \"%s\",\n"
!         "       u.usename AS \"%s\"\n"
          "FROM pg_catalog.pg_namespace n LEFT JOIN pg_catalog.pg_user u\n"
!         "       ON n.nspowner=u.usesysid\n"
!         "WHERE    n.nspname NOT LIKE 'pg_temp_%%'\n"
!         "UNION ALL\n"    /* show only local temp schema */
!         "SELECT n.nspname AS \"%s\",\n"
!         "       u.usename AS \"%s\"\n"
!         "FROM pg_catalog.pg_namespace n LEFT JOIN pg_catalog.pg_user u\n"
!         "       ON n.nspowner=u.usesysid,\n"
!         "      (SELECT current_schemas('t'::boolean)) AS curr_schemas(name)\n"
!         "WHERE    n.nspname LIKE 'pg_temp_%%' AND\n"
!         "        n.nspname = ANY(curr_schemas.name)\n",
!                       _("Name"),
!                       _("Owner"),
                        _("Name"),
                        _("Owner"));

!     processNamePattern(&buf, pattern, true, false,
                         NULL, "n.nspname", NULL,
                         NULL);