Re: Remove 1MB size limit in tsvector

Hi,

On 08/17/2017 12:23 PM, Ildus Kurbangaliev wrote:
> In my benchmarks when database fits into buffers (so it's measurement of
> the time required for the tsvectors conversion) it gives me these
> results:
>
> Without conversion:
>
> $ ./tsbench2 -database test1 -bench_time 300
> 2017/08/17 12:04:44 Number of connections: 4
> 2017/08/17 12:04:44 Database: test1
> 2017/08/17 12:09:44 Processed: 51419
>
> With conversion:
>
> $ ./tsbench2 -database test1 -bench_time 300
> 2017/08/17 12:14:31 Number of connections: 4
> 2017/08/17 12:14:31 Database: test1
> 2017/08/17 12:19:31 Processed: 43607
>
> I ran a bunch of these tests, and these results are stable on my
> machine. So in these specific tests performance regression about 15%.
>
> Same time I think this could be the worst case, because usually data
> is on disk and conversion will not affect so much to performance.
>

That seems like a fairly significant regression, TBH. I don't quite
agree we can simply assume in-memory workloads don't matter, plenty of
databases have 99% cache hit ratio (particularly when considering not
just shared buffers, but also page cache).

Can you share the benchmarks, so that others can retry running them?

regards

--
Tomas Vondra http://www.2ndQuadrant.com
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