Re: pg_upgrade problem with invalid indexes

On 12/06/2012 09:23 PM, Bruce Momjian wrote:
> On Thu, Dec 6, 2012 at 09:10:21PM -0500, Tom Lane wrote:
>> Bruce Momjian <bruce(at)momjian(dot)us> writes:
>>> On Thu, Dec 6, 2012 at 07:53:57PM -0500, Tom Lane wrote:
>>>> Because CREATE INDEX CONCURRENTLY can't drop the index if it's already
>>>> failed. It's not because we want to do that, it's an implementation
>>>> restriction of the horrid kluge that is CREATE/DROP INDEX CONCURRENTLY.
>>> Well, what is the logic that pg_dump dumps it then, even in
>>> non-binary-upgrade mode?
>> Actually, I was thinking about proposing exactly that. Ideally the
>> system should totally ignore an invalid index (we just fixed some bugs
>> in that line already). So it would be perfectly consistent for pg_dump
>> to ignore it too, with or without --binary-upgrade.
>>
>> One possible spanner in the works for pg_upgrade is that this would mean
>> there can be relation files in the database directories that it should
>> ignore (not transfer over). Dunno if that takes any logic changes.
> As soon as pg_dump stopped dumping the CREATE INDEX, pg_upgrade would
> stop creating creating it in the new cluster, and not transfer the index
> files.
>

So we'll lose the index definition and leave some files behind? This
sounds a bit messy to say the least.

Making the user fix it seems much more sensible to me. Otherwise I
suspect we'll find users who get strangely surprised when they can no
longer find any trace of an expected index in their upgraded database.

cheers

andrew