Re: pg_sample

From: "Greg Sabino Mullane" <greg(at)turnstep(dot)com>
To: pgsql-general(at)postgresql(dot)org
Subject: Re: pg_sample
Date: 2016-10-19 18:03:39
Message-ID: 46143ca644445d7eeaa2923876827da3@biglumber.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general


-----BEGIN PGP SIGNED MESSAGE-----
Hash: RIPEMD160

> I may be overseeing something, but what about dependencies between
> tables, sequencies, indexes, etc.? I guess that if one takes the first
> 100 rows of a table referenced by another table, there is no guarantee
> that in the first 100 rows of the referencing table there will not be
> some foreign key that does not exist.

The only dependency that should matter is foreign keys, and yeah, if you
have those, all bets are off; one would need to write something very custom
indeed to slurp out the data. I could envision some workarounds, but it
really depends on exactly what the OP is trying to achieve.

- --
Greg Sabino Mullane greg(at)turnstep(dot)com
End Point Corporation http://www.endpoint.com/
PGP Key: 0x14964AC8 201610191401
http://biglumber.com/x/web?pk=2529DF6AB8F79407E94445B4BC9B906714964AC8
-----BEGIN PGP SIGNATURE-----

iEYEAREDAAYFAlgHtV8ACgkQvJuQZxSWSsgrzQCglNFhkdnfg4ECC1l3l0F/Uqt0
ID4AnjGHOTR5Tsfn8MwmyBItTrOg1w7Y
=6qOO
-----END PGP SIGNATURE-----

In response to

  • Re: pg_sample at 2016-10-19 03:15:49 from Charles Clavadetscher

Browse pgsql-general by date

  From Date Subject
Next Message Alexander Farber 2016-10-19 18:35:37 Selecting records with highest timestamp - for a join
Previous Message Bruce Momjian 2016-10-19 17:42:50 Re: pg_upgrade not able to cope with pg_largeobject being in a different tablespace