Re: Proposal: global index

Erikjan Rijkers wrote:
> On 2017-08-18 11:12, Ildar Musin wrote:
> > Hi hackers,
> >
> > While we've been developing pg_pathman extension one of the most
> > frequent questions we got from our users was about global index
> > support. We cannot provide it within an extension. And I couldn't find
> > any recent discussion about someone implementing it. So I'm thinking
> > about giving it a shot and start working on a patch for postgres.
>
> Sorry to be dense but what exactly is a "Global Index"?

A global index covers all partitions of a partitioned table. It allows
you to have unique indexes across the partitioned table.

The main disadvantage of global indexes is that you need some kind of
cleanup after you drop a partition. Either make partition drop wait
until all the index pointers are removed, or you need some kind of
after-commit cleanup process that removes them afterwards (which
requires some assurance that they are really all gone). You can't let
them linger forever, or you risk a new partition that reuses the same
OID causing the whole index to become automatically corrupt.

--
Álvaro Herrera https://www.2ndQuadrant.com/
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