Re: [HACKERS] 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/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services