From e1be1df51facd3c25317c809fd72ecac8b93b4e7 Mon Sep 17 00:00:00 2001 From: Heikki Linnakangas Date: Wed, 3 Oct 2012 15:37:42 +0300 Subject: Add --sampling-rate option to pgbench. This allows logging only some fraction of transactions, greatly reducing the amount of log generated. Tomas Vondra, reviewed by Robert Haas and Jeff Janes. --- doc/src/sgml/pgbench.sgml | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'doc/src') diff --git a/doc/src/sgml/pgbench.sgml b/doc/src/sgml/pgbench.sgml index 437fceab2e4..91530abe5b0 100644 --- a/doc/src/sgml/pgbench.sgml +++ b/doc/src/sgml/pgbench.sgml @@ -316,6 +316,24 @@ pgbench options dbname + + rate + + + Sampling rate, used when writing data into the log, to reduce the + amount of log generated. If this option is given, only the specified + fraction of transactions are logged. 1.0 means all transactions will + be logged, 0.05 means only 5% of the transactions will be logged. + + + Remember to take the sampling rate into account when processing the + log file. For example, when computing tps values, you need to multiply + the numbers accordingly (e.g. with 0.01 sample rate, you'll only get + 1/100 of the actual tps). + + + + querymode @@ -750,6 +768,12 @@ END; 0 201 2513 0 1175850569 608 0 202 2038 0 1175850569 2663 + + + When running a long test on hardware that can handle a lot of transactions, + the log files can become very large. The -- cgit v1.2.3