Re: WAL file utilization question

[Alvaro Herrera <alvherre(at)commandprompt(dot)com>]

Keaton Adams wrote:

> Even with full_page_writes set to false and checkpoints taking place
> every 60 seconds or so, the amount of WAL log data generated per minute
> seems to be significant.

Stop right there.  Having checkpoints every 60 seconds is insane.  Did
you look into increasing checkpoint_segments a lot?

> So my question is this: If I kick off a transaction that loads records
> with a size of 100 bytes, does the insert for that record take 100 bytes
> in the WAL file, or is the data archived in the WAL log in page size
> (8k) portions?

Vicinity of 100 bytes, except right after checkpoints as you noted.

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.