Re: Add parallelism and glibc dependent only options to reindexdb

On Mon, Jul  1, 2019 at 09:51:12AM -0400, Alvaro Herrera wrote:
> Now that we have REINDEX CONCURRENTLY, I think reindexdb is going to
> gain more popularity.
> 
> Please don't reuse a file name as generic as "parallel.c" -- it's
> annoying when navigating source.  Maybe conn_parallel.c multiconn.c
> connscripts.c admconnection.c ...?
> 
> If your server crashes or is stopped midway during the reindex, you
> would have to start again from scratch, and it's tedious (if it's
> possible at all) to determine which indexes were missed.  I think it
> would be useful to have a two-phase mode: in the initial phase reindexdb
> computes the list of indexes to be reindexed and saves them into a work
> table somewhere.  In the second phase, it reads indexes from that table
> and processes them, marking them as done in the work table.  If the
> second phase crashes or is stopped, it can be restarted and consults the
> work table.  I would keep the work table, as it provides a bit of an
> audit trail.  It may be important to be able to run even if unable to
> create such a work table (because of the <ironic>numerous</> users that
> DROP DATABASE postgres).
> 
> Maybe we'd have two flags in the work table for each index:
> "reindex requested", "reindex done".

I think we have a similar issue with adding checksums, so let's address
with a generic framework and use it for all cases, like vacuumdb too.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
+                      Ancient Roman grave inscription +