Am 19.03.19 um 20:37 schrieb Peter J. Holzer:
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.
Strange. I saw a big difference.
What did you test?
I tested inserts.
Regards,
Thomas Güttler
--
Thomas Guettler http://www.thomas-guettler.de/
I am looking for feedback: https://github.com/guettli/programming-guidelines
