Thread: Small FSM is too large

Small FSM is too large

From
Simon Riggs
Date:
I notice that if I vacuum a 1 row table I get a FSM that is 24576 bytes
in size, or 3 database blocks.

Why is it not 1 block, or better still 0 blocks for such a small table?

-- Simon Riggs           www.2ndQuadrant.com



Re: Small FSM is too large

From
Heikki Linnakangas
Date:
On 20/06/10 13:56, Simon Riggs wrote:
> I notice that if I vacuum a 1 row table I get a FSM that is 24576 bytes
> in size, or 3 database blocks.
>
> Why is it not 1 block, or better still 0 blocks for such a small table?

It was just less code to write and test that way. The FSM tree is always 
constant height, three levels, to keep things simple.

--   Heikki Linnakangas  EnterpriseDB   http://www.enterprisedb.com