From b23160889c963dfe23d8cf1f9be64fb3c535a2d6 Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Fri, 14 Jun 2013 23:31:44 +0300
Subject: [PATCH] Add :client_id automatic variable for custom pgbench scripts.
This makes it easier to write custom scripts that have different logic for
each client.
Gurjeet Singh, with some changes by me.
---
contrib/pgbench/pgbench.c | 14 ++++++++++++++
doc/src/sgml/pgbench.sgml | 28 +++++++++++++++++++++++++++-
2 files changed, 41 insertions(+), 1 deletion(-)
diff --git a/contrib/pgbench/pgbench.c b/contrib/pgbench/pgbench.c
index 8c202bf8702..1303217086e 100644
--- a/contrib/pgbench/pgbench.c
+++ b/contrib/pgbench/pgbench.c
@@ -2544,6 +2544,20 @@ main(int argc, char **argv)
}
}
+ /*
+ * Define a :client_id variable that is unique per connection. But don't
+ * override an explicit -D switch.
+ */
+ if (getVariable(&state[0], "client_id") == NULL)
+ {
+ for (i = 0; i < nclients; i++)
+ {
+ snprintf(val, sizeof(val), "%d", i);
+ if (!putVariable(&state[i], "startup", "client_id", val))
+ exit(1);
+ }
+ }
+
if (!is_no_vacuum)
{
fprintf(stderr, "starting vacuum...");
diff --git a/doc/src/sgml/pgbench.sgml b/doc/src/sgml/pgbench.sgml
index e9900d32670..8775606affa 100644
--- a/doc/src/sgml/pgbench.sgml
+++ b/doc/src/sgml/pgbench.sgml
@@ -600,13 +600,39 @@ pgbench <optional> <replaceable>options</> </optional> <replaceable>dbname</>
Variables can be set by the command-line <option>-D</> option,
explained above, or by the meta commands explained below.
In addition to any variables preset by <option>-D</> command-line options,
- the variable <literal>scale</> is preset to the current scale factor.
+ there are a few variables that are preset automatically, listed in
+ <xref linkend="pgbench-automatic-variables">. A value specified for these
+ variables using <option>-D</> takes precedence over the automatic presets.
Once set, a variable's
value can be inserted into a SQL command by writing
<literal>:</><replaceable>variablename</>. When running more than
one client session, each session has its own set of variables.
</para>
+ <table id="pgbench-automatic-variables">
+ <title>Automatic variables</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>Variable</entry>
+ <entry>Description</entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry> <literal>scale</literal> </entry>
+ <entry>current scale factor</entry>
+ </row>
+
+ <row>
+ <entry> <literal>client_id</literal> </entry>
+ <entry>unique number identifying the client session (starts from zero)</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
<para>
Script file meta commands begin with a backslash (<literal>\</>).
Arguments to a meta command are separated by white space.
--
GitLab