Re: [PATCHES] WIP: Transportable Optimizer Mode

2008-08-06 Thread Simon Riggs

On Sat, 2008-08-02 at 20:12 +0100, Simon Riggs wrote:
 Chris,
 
 Thanks for all of those changes... added as suggested (in next version)
 
 On Wed, 2008-07-30 at 14:58 -0400, chris wrote:
 
  It's not clear to me that the plugin is actually working.
  
  When I run EXPLAIN against tables in tomtestdb, I get results
  consistent with an unanalyzed table.  So possibly the hook isn't
  being used.  Perhaps I'm using it wrongly; perhaps what I have
  documented above may suggest to you what's broken.
 
 The plugin works, but it currently extracts 0 for number of tuples. So
 you need to override that to give a different answer.
 
 I was going to add an SQL function to estimate the number of tuples in
 the same way as the optimizer does. That way we get the same answer from
 the EXPLAIN as we would have got on the main server and we don't need to
 run select count(*) against each table (unless we want to).

New version submitted together with stats hook patch on other thread.

-- 
 Simon Riggs   www.2ndQuadrant.com
 PostgreSQL Training, Services and Support


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Re: [PATCHES] WIP: Transportable Optimizer Mode

2008-08-02 Thread Simon Riggs
Chris,

Thanks for all of those changes... added as suggested (in next version)

On Wed, 2008-07-30 at 14:58 -0400, chris wrote:

 It's not clear to me that the plugin is actually working.
 
 When I run EXPLAIN against tables in tomtestdb, I get results
 consistent with an unanalyzed table.  So possibly the hook isn't
 being used.  Perhaps I'm using it wrongly; perhaps what I have
 documented above may suggest to you what's broken.

The plugin works, but it currently extracts 0 for number of tuples. So
you need to override that to give a different answer.

I was going to add an SQL function to estimate the number of tuples in
the same way as the optimizer does. That way we get the same answer from
the EXPLAIN as we would have got on the main server and we don't need to
run select count(*) against each table (unless we want to).

-- 
 Simon Riggs   www.2ndQuadrant.com
 PostgreSQL Training, Services and Support


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