Disable OpenSSL compression

I ran into a performance problem described in this thread:

http://archives.postgresql.org/pgsql-performance/2011-10/msg00249.php
continued here:
http://archives.postgresql.org/pgsql-performance/2011-11/msg00045.php

OpenSSL compresses data by default, and that causes a
performance penalty of 100% and more, at least when
SELECTing larger bytea objects.
The backend process becomes CPU bound.

From OpenSSL version 1.0.0. on, compression can be
disabled. The attached patch does that, and with that
patch I see dramatic performance improvements:

Unpatched:

samples % image name symbol name
6754 83.7861 libz.so.1.2.3 /lib64/libz.so.1.2.3
618 7.6665 libcrypto.so.1.0.0 /usr/lib64/libcrypto.so.1.0.0
534 6.6245 postgres hex_encode
95 1.1785 libc-2.12.so memcpy

Patched:

samples % image name symbol name
751 50.1670 libcrypto.so.1.0.0 /usr/lib64/libcrypto.so.1.0.0
594 39.6794 postgres hex_encode
83 5.5444 libc-2.12.so memcpy

(the test case is selecting one 27 MB bytea in text
mode over a localhost connection)

Are there any objections to this?

It is possible that this could cause a performance
regression for people who SELECT lots of compressible
data over really slow network connections, but is that
a realistic scenario?

If there are concerns about that, maybe a GUC variable like
ssl_compression (defaulting to off) would be a solution.

Yours,
Laurenz Albe