On 3/22/07, Jim Nasby <[EMAIL PROTECTED]> wrote:
Is there a safe way to deal with tables being passed into a function,
specifically in terms of what schema they're in? I can just blindly
accept a text string and hope that it's always evaluated in the
correct search_path context, but that doesn't seem so good. OTOH, if
I accept an OID, there's no great way to pass that to most of the
rest of the system... I can cast the OID to regclass, but that
doesn't get me a fully-qualified name.
It would be nice if there was a way to convert an OID into a fully-
qualified name.
I'm working on some partitioning stuff, and I'm currently writing a
function that will return the name of a partition given the parent
table and what period to partition on (ie: day, month, year, etc).
Originally, I thought I'd just accept an OID for the table name, but
I can't think of a safe way to look up that tables schema name
(because I want to return a fully qualified name). Obviously, I can
look in pg_class and pg_namespace, but someone could do a DROP TABLE
between when I do that lookup and when I actually use the name. So I
thought I'd just do a LOCK TABLE... except I need the table name to
do that. Catch-22.
You can select pg_class name in transaction by oid 'for update'. This
will block drop table, etc. from other sessions. This will only work
if you are the superuser however.
merlin
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