| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Robert Haas <robertmhaas(at)gmail(dot)com> |
| Cc: | Amit Kapila <amit(dot)kapila(at)huawei(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Readme of Buffer Management seems to have wrong sentence |
| Date: | 2012-05-22 14:01:58 |
| Message-ID: | 29007.1337695318@sss.pgh.pa.us |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> Mind you, I think this whole area of the code needs some reengineering
> for better performance, but I'm not sure this is the right place to
> start. What I think is really bad is that we're forcing every
> BufferAlloc() to iterate over buffers checking whether each one is
> evictable.
Well, keep in mind that that action is not merely there to obtain a
victim buffer; it is also maintaining the global LRU state (by
decrementing the usage counts of buffers it passes over). I don't think
you can change it to simply look only at a predetermined freelist
without seriously compromising the overall quality of our buffer
replacement decisions.
regards, tom lane
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Robert Haas | 2012-05-22 14:04:25 | Re: incorrect handling of the timeout in pg_receivexlog |
| Previous Message | Robert Haas | 2012-05-22 13:50:38 | Re: "could not open relation with OID" errors after promoting the standby to master |