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help / color / mirror / Atom feedFrom: Marko Ristola <[email protected]>
To: [email protected]
Subject: PostgreSQL ODBC mylog() uses lots of CPU in INTEGER field SQL query
Date: Fri, 7 May 2021 21:13:18 +0300
Message-ID: <CALndGf+qOJc6ZPfEAJgs_+CkE01QtEMQVEumGURHzzA+MYOuwg@mail.gmail.com> (raw)
I did a query of 4 million rows into an INTEGER field.
Linux perf shows following profile (hottest functions):
9.91% bc_sqlselect psqlodbcw.so [.] mylog
9.64% bc_sqlselect psqlodbcw.so [.]
QR_read_a_tuple_from_db
4.83% bc_sqlselect psqlodbcw.so [.]
copy_and_convert_field
4.57% bc_sqlselect libpthread-2.17.so [.] pthread_mutex_unlock
4.51% bc_sqlselect libpthread-2.17.so [.] pthread_mutex_lock
4.40% bc_sqlselect psqlodbcw.so [.]
SOCK_get_next_n_bytes.part.2
3.93% bc_sqlselect psqlodbcw.so [.] PGAPI_ExtendedFetch
Following patch removes the only mylog() call (not a macro)
from the PostgreSQL ODBC driver from consuming CPU:
(MYLOG() macro is used to avoid the heavy mylog() call.)
diff --git a/results.c b/results.c
index 1f6a12c..ec89600 100644
--- a/results.c
+++ b/results.c
@@ -4632,7 +4632,6 @@ SC_pos_add(StatementClass *stmt,
goto cleanup;
}
MYLOG(0, "addstr=%s\n", addstr.data);
- mylog("addstr=%s\n", addstr.data);
s.qstmt->exec_start_row = s.qstmt->exec_end_row = s.irow;
s.updyes = TRUE;
ret = PGAPI_ExecDirect(hstmt, (SQLCHAR *) addstr.data,
SQL_NTS, 0);
Best Regards, Marko Ristola
--
Marko Ristola
Software developer
BC Platforms
m. +358 40 593 2182
e. [email protected]
w. www.bcplatforms.com
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Subject: Re: PostgreSQL ODBC mylog() uses lots of CPU in INTEGER field SQL query
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