[sorry, previous mail was sent earlier than expected]

> First, the proposed changes in this email are to be used at least for

> PostgreSQL extensions, maybe for core.

>

> Purpose is to offer better monitoring/tracking of the hot/cold areas (and

> read/write paterns) in the tables and indexes, in PostgreSQL those are by default

> written in segments of 1GB.

>

> There are some possible usecase already:

>

> * planning of hardware upgrade

> * easier configuration setup (both PostgreSQL and linux)

> * provide more informations to the planner/executor of PostgreSQL

>

> My ideas so far are to

>

> * improve mincore() in linux and add it information like in freeBSD (at

> least adding 'mincore_modified' to track clean vs dirty pages).

> * adding fincore() to make the information easier to grab from PostgreSQL (no

> mmap)

> * maybe some access to those stats in /proc/

>

> It makes years that libprefetch, mincore() and fincore() are discussed on linux

> mailling lists. And they got a good feedback... So I hope it is ok to keep on

> those and provide updated patches.

Johannes, I add you in CC because you're the last one who proposed something.

Can I update your patch with previous suggestions from reviewers ?

I'm also asking for feedback in this area, others ideas are very welcome.

--

Cédric Villemain +33 (0)6 20 30 22 52

http://2ndQuadrant.fr/

PostgreSQL: Support 24x7 - Développement, Expertise et Formation