Re: W-TinyLfu for cache eviction

On Mon, Dec 14, 2015 at 12:18 PM, Vladimir Sitnikov <
sitnikov(dot)vladimir(at)gmail(dot)com> wrote:
> > a global lock would be good enough for a proof of concept that only
> evaluates cache hit ratios.
>
> I think emulator can be used to check hit ratios. That way we can see
> how different algorithms affect hit ratio.
>
> Is there a set of traces of "buffer load events"? (I did some Google
> searches like "postgresql buffer cache trace" with no luck)
> Is there an option that enables tracing of each requested buffer Id?
>

To get the detailed trace for each buffer, I think you can use dynamic
tracing as explained in documentation [1].

Another simple way could be to use:
Explain (Analyze, Buffers) <sql_statement>

This will give blocks hit and read numbers which could be useful in your
experiments.

[1] - http://www.postgresql.org/docs/devel/static/dynamic-trace.html

With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com