Re: Support for REINDEX CONCURRENTLY

Hi all,

Please find attached a new set of 3 patches for REINDEX CONCURRENTLY (v11).
- 20130214_1_remove_reltoastidxid.patch
- 20130214_2_reindex_concurrently_v11.patch
- 20130214_3_reindex_concurrently_docs_v11.patch
Patch 1 needs to be applied before patches 2 and 3.

20130214_1_remove_reltoastidxid.patch is the patch removing reltoastidxid
(approach mentioned by Tom) to allow server to manipulate multiple indexes
of toast relations. Catalog views, system functions and pg_upgrade have
been updated in consequence by replacing reltoastidxid use by a join on
pg_index/pg_class. All the functions of tuptoaster.c now use
RelationGetIndexList to fetch the list of indexes on which depend a given
toast relation. There are no warnings, regressions are passing (here only
an update of rules.out and oidjoins has been necessary).
20130214_2_reindex_concurrently_v11.patch depends on patch 1. It includes
the feature with all the fixes requested by Andres in his previous reviews.
Regressions are passing and I haven't seen any warnings. in this patch
concurrent rebuild of toast indexes is fully supported thanks to patch 1.
The kludge used in previous version to change reltoastidxid when swapping
indexes is not needed anymore, making swap code far cleaner.
20130214_3_reindex_concurrently_docs_v11.patch includes the documentation
of REINDEX CONCURRENTLY. This might need some reshuffling with what is
written for CREATE INDEX CONCURRENTLY.

I am now pretty happy with the way implementation is done, so I think that
the basic implementation architecture does not need to be changed.
Andres, I think that only a single round of review would be necessary now
before setting this patch as ready for committer. Thoughts?

Comments, as well as reviews are welcome.
-- 
Michael