Re: How do i compare 2 postgresql instanses ?

["Michael Nacos" <m.nacos@xxxxxxxxx>]

Hello there. Simple counts can certainly prove two databases are not the same version. But what if you actually want to look at the data? I have been thinking about row checksums, would you say this would be a reasonable way of verifying two databases are equivalent? I have many other things on my mind, so I haven't tried implementing this yet.

Michael

you could write a little program (awk) to produce an sql file of the form:
select count(*) from airlines;
select count(*) from airports;
select count(*) from airticket;
select count(*) from airticketflights;
....
select count(*) from zzzobjects;

and then run it against the two databases, and diff the outputs.
If the outputs are not identical then you have 2 different databases,
otherwise you have to search more to know the answer.
So this technique can prove that yours DBs are *not* identical, but does not say anything
about the opposite.

--
Achilleas Mantzios