--On Montag, August 03, 2009 15:11:08 -0400 Tom Lane <t...@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     total
time   seconds   seconds    calls   s/call   s/call  name
37.81    157.22   157.22    97847     0.00     0.00  pglz_compress
20.25    241.43    84.21   141398     0.00     0.00  CopyReadLine
14.44    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

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