Re: [HACKERS] GSoC on WAL-logging hash indexes

On Sun, Mar 2, 2014 at 2:38 PM, Tan Tran <tankimtran(at)gmail(dot)com> wrote:
> 2. Proposal
> As a GSoC student, I will implement WAL recovery of hash indexes using the
> other index types' WAL code as a guide. Roughly, I will:
> - Devise a way to store and retrieve hashing data within the XLog data
> structures.
> - In the existing skeleton for hash_redo(XLogRecPtr lsn, XLogRecord *record)
> in hash.c, branch to code for the various redo operations: creating an
> index, inserting into an index, deleting an index, and page operations
> (split, delete, update?).
> - Code each branch by drawing on examples from btree_redo, gin_redo, and
> gist_redo, the existing XLog code of the other index types.

Unfortunately, I don't believe that it's possible to do this easily
today because of the way bucket splits are handled. I wrote about
this previously here, with an idea for solving the problem:

http://www.postgresql.org/message-id/CA+TgmoZyMoJSrFxHXQ06G8jhjXQcsKvDiHB_8z_7nc7hj7iHYQ@mail.gmail.com

Sadly, no one responded. :-(

--
Robert Haas
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