"Jim C. Nasby" <jim@nasby.net> wrote:
> > I'd like to add some kind of logical flavors to max_fsm_pages
> > and max_dsm_pages.
>
> In the meantime, I'm not sure if it makes sense to tie the FSM size to
> the DSM size, since each FSM page requires 48x the storage of a DSM
> page. I think there's also a lot of cases where FSM size will not scale
> the same was DSM size will, such as when there's historical data in the
> database.
I see. We need separate variables for FSM and DSM.
Here is a new proposal for replacements of variables at Free Space Map
section in postgresql.conf. Are these changes acceptable? If ok, I'd
like to rewrite codes using them.
# - Space Management -
managed_relations = 1000 # min 100, ~120 bytes each
managed_freespaces = 2GB # 6 bytes of shared memory per 8KB
managed_deadspaces = 8GB # 4KB of shared memory per 32MB
managed_relations: Replacement of max_fsm_relations. It is also used by DSM.
managed_freespaces: Replacement of max_fsm_pages. The meaning is not changed, but can be set in bytes.
managed_deadspaces: A new parameter for DSM. It might be better to be scaled with whole database size.
Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center
