Re: Clarification to catalog-pg-class - Mailing list pgsql-docs

Josh Berkus wrote:
> Bruce,
>
> >> Currently, catalog-pg-class is a bit confusing as to where FKs are
> >> tracked in pg_class.  Please update the lines for relchecks and
> >> reltriggers to read:
> >>
> >> relchecks    int2          Number of check constraints on the table (but not
> >> other types of constraints); see pg_constraint catalog
> >
> > Uh, why do we have to say "but" when we clearly say "check constraints"?
> > Do we need to say "CHECK" contraints?
>
> Because I've encountered two people on IRC (and a client) who were
> confused about this, and it confused me briefly when I fielded their
> questions.  Saying "CHECK constraints" would also probably do it, or
> saying "check constraints (only)"

Uppercase done, with <literal> tag.

> BTW, why do we still have relukeys etc. around?  If we haven't used them
> in 5 versions, shouldn't we purge them?

Uh, that one is gone now:

          Table "pg_catalog.pg_class"
         Column     |   Type    | Modifiers
    ----------------+-----------+-----------
     relname        | name      | not null
     relnamespace   | oid       | not null
     reltype        | oid       | not null
     relowner       | oid       | not null
     relam          | oid       | not null
     relfilenode    | oid       | not null
     reltablespace  | oid       | not null
     relpages       | integer   | not null
     reltuples      | real      | not null
     reltoastrelid  | oid       | not null
     reltoastidxid  | oid       | not null
     relhasindex    | boolean   | not null
     relisshared    | boolean   | not null
     relkind        | "char"    | not null
     relnatts       | smallint  | not null
     relchecks      | smallint  | not null
     relhasoids     | boolean   | not null
     relhaspkey     | boolean   | not null
     relhasrules    | boolean   | not null
     relhastriggers | boolean   | not null
     relhassubclass | boolean   | not null
     relfrozenxid   | xid       | not null
     relacl         | aclitem[] |
     reloptions     | text[]    |

>
> >
> >> reltriggers    int2         Number of triggers on the table, including
> >> constraint-triggers for foreign keys; see pg_trigger catalog
> >
> > pg_class doesn't have that column anymore, it has relhastriggers.
>
> Ah.  Where are we tracking FKs at this point, then?

The count was only used to determine if we should check for triggers, so
we now use a boolean;  the code checks are the same.

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + If your life is a hard drive, Christ can be your backup. +