Re: REINDEX CONCURRENTLY 2.0

On Fri, Feb 17, 2017 at 10:43 PM, Andreas Karlsson <andreas(at)proxel(dot)se> wrote:
> Thinking about this makes me wonder about why you decided to use a
> transaction per index in many of the steps rather than a transaction per
> step. Most steps should be quick. The only steps I think the makes sense to
> have a transaction per table are.

I don't recall all the details to be honest :)

> 1) When building indexes to avoid long running transactions.
> 2) When validating the new indexes, also to avoid long running transactions.
>
> But when swapping the indexes or when dropping the old indexes I do not see
> any reason to not just use one transaction per step since we do not even
> have to wait for any locks (other than WaitForLockers which we just want to
> call once anyway since all indexes relate to the same table).

Perhaps, this really needs a careful lookup.

By the way, as this patch is showing up for the first time in this
development cycle, would it be allowed in the last commit fest? That's
not a patch in the easy category, far from that, but it does not
present a new concept.
--
Michael