Обсуждение: Mapping a Data File Back to a Table

So I've been digging through a database on an embedded device for two
days trying to figure out which table some data is stored in. There
are litterally 1000 tables in the database and I haven't come across
the right one(s) yet. I know that the data I'm looking for is stored
in /var/lib/pgsql/data/base/16384/2613 from strings and grep. Is there
any way to map this back to a table or group of tables? Any insight
would be greatly appreciated!

It was stored in pg_largeobject based on the OID.


On Fri, Jan 04, 2013 at 11:09:33AM -0700, Greg Schenzel wrote:
> So I've been digging through a database on an embedded device for two
> days trying to figure out which table some data is stored in. There
> are litterally 1000 tables in the database and I haven't come across
> the right one(s) yet. I know that the data I'm looking for is stored
> in /var/lib/pgsql/data/base/16384/2613 from strings and grep. Is there
> any way to map this back to a table or group of tables? Any insight
> would be greatly appreciated!
>

Greg Schenzel <inittab@unixdev.net> writes:
> So I've been digging through a database on an embedded device for two
> days trying to figure out which table some data is stored in. There
> are litterally 1000 tables in the database and I haven't come across
> the right one(s) yet. I know that the data I'm looking for is stored
> in /var/lib/pgsql/data/base/16384/2613 from strings and grep. Is there
> any way to map this back to a table or group of tables? Any insight
> would be greatly appreciated!

Just for the record, the 16384 is the OID of a database (look at
pg_database.oid) and 2613 is the filenode of a table (look at
pg_class.relfilenode in the relevant database).  contrib/oid2name
can help mechanize this but personally I never bother with that.

See http://www.postgresql.org/docs/9.2/static/storage.html
for the authoritative skinny (but note this stuff does change
across releases, so be sure to read the correct version of the docs).

            regards, tom lane