Re: md5 of table

md5 has size limitations, the second approach seems more practical.

Στις Thursday 01 September 2011 12:30:45 ο/η Karsten Hilbert έγραψε:
> On Thu, Sep 01, 2011 at 11:47:24AM +0300, Sim Zacks wrote:
>
> > Is there a way to get an md5 or other hash of an entire table?
> >
> > I want to be able to easily compare 2 tables in different databases.
> >
> > I thought about using dblink and the EXCEPT query, but then I need to
> > know the field list of each query result, which is a pain in the
> > butt.
> >
> > If I could return an md5 of the entire table, then I could check if
> > the tables have the same hash and be confident enough that the tables
> > were identical.
>
> One option might be to pg_dump in an appropriate format and
> md5-compare the output ?
>
> Another option might be to
>
> - cross-check columns/column types
>     - query from information_schema
> - compare row counts
>     - may need a lock
> - compare table sizes
>     - may need vaccum ?
>
> If all three match that may be good enough ?
>
> Karsten
> --
> GPG key ID E4071346 @ gpg-keyserver.de
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>



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Achilleas Mantzios