Re: [GENERAL] pg_migrator not setting values of sequences? - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: [GENERAL] pg_migrator not setting values of sequences?
Date
Msg-id 200907160407.n6G47qN09594@momjian.us
Whole thread Raw
In response to Re: [GENERAL] pg_migrator not setting values of sequences?  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Tom Lane wrote:
> Alvaro Herrera <alvherre@commandprompt.com> writes:
> > Tom Lane wrote:
> >> The most effective solution might be to revert the change in pg_migrator
> >> and instead have pg_dump interpret --binary-upgrade --schema-only to
> >> include the data for sequences.  It seems ugly as sin though :-(
> 
> > It seems cleaner to have a pg_dump --dump-all-sequences or some such.
> 
> Well, that's assuming that we think there's any point in having a
> "clean" definition.
> 
> I have been poking at the pg_largeobject problem previously mentioned,
> and have found out that there are actually two bugs:
>     * pg_largeobject_loid_pn_index is not transferred
>     * large object comments are not transferred

Nice catch, thanks.

> The first of these is clearly pg_migrator's responsibility to fix,
> but I think we have to get pg_dump to handle the second one.  Again,
> the problem here is that the dividing line between "schema" and "data"
> isn't drawn in a place that suits pg_migrator's needs --- pg_dump
> thinks that both LOs and their comments are "data".
> 
> Do you really want to propose that we invent, and document, two new
> switches to expose these behaviors?  I think just hacking the behavior
> on the basis of --binary-upgrade is the thing to do.  In fact, I'm
> thinking that we should remove the --schema-only switch from
> pg_migrator's call of pg_dump, and just have --binary-upgrade
> automatically know which things it is supposed to dump or not.

Agreed.

> [ pokes at it some more... ]  Oooh, there's another issue:
> the backend rejects COMMENT ON LARGE OBJECT if the specified OID
> doesn't exist in pg_largeobject.  This is gonna be a problem.
> pg_migrator wants to import the pg_dump output before it's moved
> any tables.
> 
> I wonder if it's sane to do the physical move of pg_largeobject
> before we import the dump?

Not sure.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + If your life is a hard drive, Christ can be your backup. +


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