--On Mittwoch, Mai 06, 2009 19:04:21 -0400 Tom Lane <tgl@sss.pgh.pa.us>
wrote:
> So I'm now persuaded that a better textual representation for bytea
> should indeed make things noticeably better here. It would be
> useful though to cross-check this thought by profiling a case that
> dumps a comparable volume of text data that contains no backslashes...
This is a profiling result of the same data converted into a printable text
format without any backslashes. The data amount is quite the same and as
you already guessed, calls to appendBinaryStringInfo() and friends gives
the expected numbers:
time seconds seconds calls s/call s/call name35.13 24.67 24.67 134488 0.00 0.00
byteaout32.61 47.57 22.90 134488 0.00 0.00 CopyOneRowTo28.92 67.88 20.31 85967 0.00
0.00 pglz_decompress 0.67 68.35 0.47 4955300 0.00 0.00
hash_search_with_hash_value 0.28 68.55 0.20 11643046 0.00 0.00 LWLockRelease 0.28 68.75 0.20
4828896 0.00 0.00 index_getnext 0.24 68.92 0.17 1208577 0.00 0.00 StrategyGetBuffer 0.23
69.08 0.16 11643046 0.00 0.00 LWLockAcquire
... 0.00 70.23 0.00 134498 0.00 0.00 enlargeStringInfo 0.00 70.23 0.00 134497 0.00
0.00 appendBinaryStringInfo 0.00 70.23 0.00 134490 0.00 0.00 AllocSetReset 0.00 70.23 0.00
134490 0.00 0.00 resetStringInfo 0.00 70.23 0.00 134488 0.00 0.00 CopySendChar 0.00
70.23 0.00 134488 0.00 0.00 CopySendEndOfRow
-- Thanks
Bernd