Indeed, hypothetical indexes are good to check potentially good configurations without harming the whole system with actual index creation. Please observer that we've added an "explain hypothetical" command, that will include plans considering hypothetical indexes! We'll try to add a simple case study that would help those wondering about this project.

Sergio

On 3/12/2010 08:06, Richard Huxton wrote:
On 03/12/10 08:14, Jeroen Vermeulen wrote:
On 2010-12-02 00:48, Ana Carolina Brito de Almeida wrote:

We would like to inform you all that our extension to PostgreSQL, that
includes hypothetical indexes (and soon index self-tuning), is
available through a sourgeforge project.

Looking at the sourceforge page, I'm left with one burning question:
what are they for?

I believe they're for performance testing. Add hypothetical index (takes very little time). Check estimated costs with EXPLAIN. If good, add real index (takes lots of time).

Of course, they're also good for indexing hypothetical data ;-)


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