Re: Performance of ByteA: ascii vs binary

On 2019-03-18 15:33:17 +0100, Thomas Güttler wrote:
> I did some benchmarking and in my setup there was major
> performance difference.
> 
> I tested a ByteA column.
> 
> If I used ascii data the tests took 52 seconds.
> If I used random binary data the test took 250 seconds.
> 
> binary data is (roughly) five times slower than ascii data?
> 
> Is this a know fact, or is there something wrong with my benchmark?
> 
> I used Python and psycopg2.

I don't see this here (Debian 9, Python 3,5, psycopg2 2.7.6, PostgreSQL
9.5).

I modified my bench-bytea script (https://github.com/hjp/blob-bench) to
restrict the byte values to printable ASCII (32 .. 126). There was
absolutely no difference, as the attached graph shows.

        hp

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