postgres/contrib/pgbench

pgbench 1.2 README		2000/1/15 Tatsuo Ishii (t-ishii@sra.co.jp)

o What is pgbench?

  pgbench is a simple program to run a benchmark test sort of
  "TPC-B". pgbench is a client application of PostgreSQL and runs
  with PostgreSQL only. It performs lots of small and simple
  transactions including select/update/insert operations then
  calculates number of transactions successfully completed within a
  second (transactions per second, tps). Targeting data includes a
  table with at least 100k tuples.

  Example outputs from pgbench look like:

	number of clients: 4
	number of transactions per client: 100
	number of processed transactions: 400/400
	tps = 19.875015(including connections establishing)
	tps = 20.098827(excluding connections establishing)

  Similar program called "JDBCBench" already exists, but it requires
  Java that may not be available on every platform. Moreover some
  people concerned about the overhead of Java that might lead
  inaccurate results. So I decided to write in pure C, and named
  it "pgbench."

o features of pgbench

  - pgbench is written in C using libpq only. So it is very portable
    and easy to install.

  - pgbench can simulate concurrent connections using asynchronous
    capability of libpq. No threading is required.

o How to install pgbench

 (1) Edit the first line in Makefile

	POSTGRESHOME = /usr/local/pgsql

     so that it points to the directory where PostgreSQL installed.

 (2) Run configure

 (3) Run make. You will see an executable file "pgbench" there.

o How to use pgbench?

  (1) Initialize database by:

	pgbench -i <dbname>

      where <dbname> is the name of database. pgbench uses four tables
      accounts, branches, history and tellers. These tables will be
      destroyed. Be very carefully if you have tables having same
      names. Default test data contains:

	table		# of tuples
	-------------------------
	branches	1
	tellers		10
	accounts	100000
	history		0

	You can increase the number of tuples by using -s option. See
	below.

  (2) Run the benchmark test

	pgbench <dbname>

      The default configuration is:

	number of clients: 1
	number of transactions per client: 10

o options

  pgbench has number of options.

	-h hostname
		hostname where the backend is running. If this option
		is omitted, pgbench will connect to the localhost via
		Unix domain socket.

	-p port
		the port number that the backend is accepting. default is
		5432.

	-c number_of_clients
		Number of clients simulated. default is 1.

	-t number_of_transactions
		Number of transactions each client runs. default is 10.

	-s scaling_factor
		this should be used with -i (initialize) option.
		number of tuples generated will be multiple of the
		scaling factor. For example, -s 100 will imply 10M
		(10,000,000) tuples in the accounts table.
		default is 1.

	-n
		No vacuuming and cleaning the history table prior the
		test is performed.

	-v
		Do vacuuming before testing. This will take some time.
		Without both -n and -v pgbench will vacuum tellers and
		branches tables only.

	-S
		Perform select only transactions instead of TPC-B.

	-d
		debug option.


o What is the "transaction" actually performed in pgbench?

  (1) begin;

  (2) update accounts set abalance = abalance + :delta where aid = :aid;

  (3) select abalance from accounts where aid = :aid;

  (4) update tellers set tbalance = tbalance + :delta where tid = :tid;

  (5) update branches set bbalance = bbalance + :delta where bid = :bid;

  (6) insert into history(tid,bid,aid,delta) values(:tid,:bid,:aid,:delta);

  (7) end;

o License?

Basically it is same as BSD license. See pgbench.c for more details.

o History

2000/1/15 pgbench-1.2 contributed to PostgreSQL
	* Add -v option

1999/09/29 pgbench-1.1 released
	* Apply cygwin patches contributed by Yutaka Tanida
	* More robust when backends die
	* Add -S option (select only)

1999/09/04 pgbench-1.0 released