Re: 9.3 Pre-proposal: Range Merge Join

From: Simon Riggs <simon(at)2ndQuadrant(dot)com>
To: Jeff Davis <pgsql(at)j-davis(dot)com>
Cc: Alexander Korotkov <aekorotkov(at)gmail(dot)com>, Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: 9.3 Pre-proposal: Range Merge Join
Date: 2012-04-16 21:20:03
Message-ID: CA+U5nMJ_c=AfoEmbceR_F8w8j_LYY+Ax0CLU8vjveDeYoFzEFg@mail.gmail.com
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On Mon, Apr 16, 2012 at 9:12 PM, Jeff Davis <pgsql(at)j-davis(dot)com> wrote:

> That had occurred to me, but I was hesitant to only use temp indexes. It
> still doesn't really offer a good solution when both sides of the join
> are relatively large (because of random I/O). Also the build speed of
> the index would be more important than it is now.

The thing I like most about temp indexes is that they needn't be temporary.

I'd like to see something along the lines of demand-created optional
indexes, that we reclaim space/maintenance overhead on according to
some cache management scheme. More space you have, the more of the
important ones hang around. The rough same idea applies to
materialised views.

--
 Simon Riggs                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services

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