Skip site navigation (1) Skip section navigation (2)

Re: suggestion: set default statistics to 100 for numerics

From: Joseph Shraibman <jks(at)selectacast(dot)net>
To: Alvaro Herrera <alvherre(at)dcc(dot)uchile(dot)cl>
Subject: Re: suggestion: set default statistics to 100 for numerics
Date: 2004-07-01 23:30:25
Message-ID: 40E49E91.2050201@selectacast.net (view raw or flat)
Thread:
Lists: pgsql-hackers
Alvaro Herrera wrote:
> On Wed, Jun 30, 2004 at 10:56:53PM -0400, Joseph Shraibman wrote:
> 
>>Seeing how small storage for a number type is compared to a text type, 
>>and seeing how they tend to be queried on a lot, shouldn't it be 
>>reasonable for the default stats number for numerics to be 100 instead 
>>of 10?
> 
> 
> The problem is not only storage space, but also the optimizer runtime;
> which would have to munge the larger amount of data ... not sure if this
> is critical but enlarging it by default for all numeric columns may not
> be desirable.

I don't think the optimizer run time is that much longer in absolute 
terms.  The only reason I suggest it is that even experienced postgres 
users probably don't think about this often enough
> 
> Anyway ISTM a better rule would be enlarging the default stats number
> for columns that are part of an index, rather than using the datatype.
> 
That has merit too, but I think text fields are queried on and indexed 
less and would take up much more room in the stats table.

In response to

pgsql-hackers by date

Next:From: Mike RylanderDate: 2004-07-01 23:34:19
Subject: Re: Quick question regarding tablespaces
Previous:From: Marc G. FournierDate: 2004-07-01 23:24:27
Subject: Re: pgFoundry Open For Business

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group