--On Montag, August 03, 2009 15:11:08 -0400 Tom Lane <tgl@sss.pgh.pa.us>
wrote:
> I'm starting to look at this patch. I observe that it's setting the
> default output format to HEX. If changing the default behavior was
> agreed to, or even discussed, I do not remember where. Shouldn't the
> default stay the same?
I would prefer it to be the default at least for pg_dump, if we can get
some significant performance improvement for both, dump and restore from
it. However, here are some current performance numbers (taken from today,
since yesterday i had some trouble to get on the machine):
I did some restore testing based on the following flow:
BEGIN;
TRUNCATE ... ;
COPY testtable FROM ... ;
ROLLBACK;
with bytea_output = 'escape' i get
Time: 1478801,770 ms
where bytea_output = 'hex' gives:
Time: 1448871,566 ms
So 'hex' is slightly faster on this machine, but not in the numbers i would
have expected. The hex-based restore gives the following profile:
Each sample counts as 0.01 seconds. % cumulative self self totaltime seconds seconds calls
s/call s/call name37.81 157.22 157.22 97847 0.00 0.00 pglz_compress20.25 241.43 84.21
141398 0.00 0.00 CopyReadLine14.44 301.48 60.05 3605691992 0.00 0.00 get_hex 8.29 335.96
34.48 141397 0.00 0.00 hex_decode 7.99 369.20 33.24 1 33.24 398.14 DoCopy 3.95 385.63
16.43 esc_enc_len 0.71 388.58 2.95 137268286 0.00 0.00 _bt_compare 0.54
390.81 2.23 7209863 0.00 0.00 XLogInsert 0.48 392.81 2.00 49329221 0.00 0.00
hash_search_with_hash_value 0.43 394.59 1.78 91132579 0.00 0.00 LWLockAcquire 0.42 396.34 1.75
92250421 0.00 0.00 LWLockRelease 0.42 398.08 1.75 30477526 0.00 0.00 ReadBuffer_common 0.20
398.93 0.85 28686690 0.00 0.00 PinBuffer 0.18 399.67 0.74 21541372 0.00 0.00 _bt_binsrch
0.16 400.34 0.67 39278753 0.00 0.00 AllocSetAlloc
-- Thanks
Bernd
