Re: Dynamically sizing FSM?

Tom Lane <tgl@sss.pgh.pa.us> wrote:

> I'm of the opinion that the solution to FSM being fixed-size is to keep
> it somewhere else, ie, on disk (possibly with some sort of cache in
> shared memory for currently-used entries).

What do you think dynamic allocation from shared_buffers? ie, remove
a buffer page in the shared buffer pool and use the 8kB of memory
for another purpose. To be sure, we don't free from out-of-FSM-memory,
but it can get rid of deciding the amount of FSM buffers.

I think we could use the above as "shared memory allocator".
It is useful for Dead Space Map, shared prepared statements, and so on.

Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center