Re: New/Revised TODO? Gathering actual read performance data for use by planner

On Wed, May 25, 2011 at 10:17 AM, Greg Smith <greg@2ndquadrant.com> wrote:
>> This data would probably need to be kept separately for each table or
>> index, as some tables or indexes
>> may be mostly or fully in cache or on faster physical media than others,
>> although in the absence of other
>> data about a specific table or index, data about other relations in the
>> same tablespace might be of some use.
>
> This is the important part.  Model how the data needs to get stored such
> that the optimizer can make decisions using it, and I consider it easy to
> figure out how it will get populated later.

I basically agree.  There have been several recent discussions of this
topic on both -hackers and -performance; it is likely that the TODO
needs to be updated with some more recent links.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company