and number of transactions per client); these will be equal unless the run

failed before completion. (In <option>-T</> mode, only the actual

number of transactions is printed.)

The next two lines report the number of

transactions with serialization and deadlock failures; unlike other errors

transactions with these ones don't fail and continue run normally, but

transaction result is rolled back.

And the last two lines report the number of transactions per second,

The next two lines report the number of transactions with serialization and

deadlock failures. With such errors, transactions do not fail and continue

running normally, but the transaction result is rolled back.

The last two lines report the number of transactions per second,

figured with and without counting the time to start database sessions.

</para>

</varlistentry>

<varlistentry>

<term><option>-I</option> <replaceable>isolationlevel</></term>

<term><option>--default-isolation-level=</option><replaceable>isolationlevel</></term>

<term><option>-I</option> <replaceable>isolation_level</></term>

<term><option>--default-isolation-level=</option><replaceable>isolation_level</></term>

<listitem>

<para>

Set default transaction isolation level. Use next abbreviations for

<replaceable>isolationlevel</>:

Set the default transaction isolation level:

<itemizedlist>

<listitem>

<para><literal>RC</>:set default transaction isolation level asRead Committed.</para>

<para><literal>RC</>: Read Committed</para>

</listitem>

<listitem>

<para><literal>RR</>:set default transaction isolation level asRepeatable Read.</para>

<para><literal>RR</>: Repeatable Read</para>

</listitem>

<listitem>

<para><literal>S</>:set default transaction isolation level asSerializable.</para>

<para><literal>S</>: Serializable</para>

</listitem>

</itemizedlist>

The default isRead Committed isolation level.(See

<xref linkend="transaction-iso"> for more information.)

By default,Read Committed isolation level is used.For more

information, see<xref linkend="transaction-iso">.

</para>

</listitem>

</varlistentry>

<listitem>

<para>

Show progress report every <replaceable>sec</> seconds. The report

includes the time since the beginning of the run andnext

characteristics since the last report: the tps, the number of

transactionswith serialization and deadlock failures, and the

transaction latencyaverage and standard deviation. Under throttling

(<option>-R</>), thelatency is computed with respect to the transaction

scheduled starttime, not the actual transaction beginning time, thus it

also includesthe average schedule lag time.

includes the time since the beginning of the run andthe following

statistics since the last report: the tps, the number of transactions

with serialization and deadlock failures, and the transaction latency

average and standard deviation. Under throttling (<option>-R</>), the

latency is computed with respect to the transaction scheduled start

time, not the actual transaction beginning time, thus it also includes

the average schedule lag time.

</para>

</listitem>

</varlistentry>

<para>

Report the average per-statement latency (execution time from the

perspective of the client) of each command after the benchmark

finishes (with the number of serialization and deadlock failures for

each command if it is used with <option>--report-failures</> option).

See below for details.

finishes. You can use this option together with the

<option>--report-failures</> option to get the number of serialization

and deadlock failures for each command.

For details, see <xref linkend="per-statement-latencies-failures"

endterm="per-statement-latencies-failures-title">.

</para>

</listitem>

</varlistentry>

<listitem>

<para>

Report the number of serialization and deadlock failures for each

command after the benchmark finishes (with the average per-statement

latencies of each command if it is used with <option>-r</> option). See

below for details.

command after the benchmark finishes. You can use this option together

with the <option>--report-latencies</> option to get the average

per-statement latencies of each command.

For details, see <xref linkend="per-statement-latencies-failures"

endterm="per-statement-latencies-failures-title">.

</para>

</listitem>

</varlistentry>

When both <option>--rate</> and <option>--latency-limit</> are used,

the <replaceable>time</> for a skipped transaction will be reported as

<literal>skipped</>.

If transaction has serialization / deadlock failure or them both (last thing

is possible if used script contains several transactions; see

<xref linkend="transactions-and-scripts"

endterm="transactions-and-scripts-title"> for more information), its

<replaceable>time</> will be reported as <literal>serialization failure</> /

<literal>deadlock failure</> /

<literal>serialization and deadlock failures</> appropriately.

If a transaction has serialization and/or deadlock failures, its

<replaceable>time</> will be reported as <literal>serialization failure</>,

<literal>deadlock failure</>, or

<literal>serialization and deadlock failures</>, respectively.

</para>

<note>

<para>

Transactions can have both serialization and deadlock failures if the

used script contained several transactions. See

<xref linkend="transactions-and-scripts"

endterm="transactions-and-scripts-title"> for more information.

</para>

</note>

<para>

Here is a snippet of the log file generated:

</para>

<para>

Example with serialization, deadlockandboth these failures:

Example with serializationanddeadlock failures:

<screen>

1 128 24968 0 1496759158 426984

0 129 serialization failure 0 1496759158 427023

format time stamp), <replaceable>num_of_transactions</> is the number of transactions

within the interval, <replaceable>num_serialization_failures_transactions</>

and <replaceable>num_deadlock_failures_transactions</> are the numbers of

transactions withappropriate failures within the interval, <replaceable>

transactions withthe corresponding failures within the interval, <replaceable>

latency_sum</replaceable> is a sum of latencies (so you can compute average

latency easily). The following two fields are useful for variance estimation

- <replaceable>latency_sum</> is a sum of latencies and <replaceable>

</refsect2>

<refsect2>

<title>Per-Statement Latencies and Failures</title>

<refsect2 id="per-statement-latencies-failures">

<title id="per-statement-latencies-failures-title">Per-Statement Latencies and Failures</title>

<para>

There're two options to get some per-statement characteristics: <option>-r</>

and <option>--report-failures</> (they can be combined together). All values

are computed for each statement executed by every client and are reported

after the benchmark has finished. With the <option>-r</> option,

<application>pgbench</> collects the elapsed transaction time of each

statement. It then reports an average of those values, referred to as the

latency for each statement. With the <option>--report-failures</> option,

<application>pgbench</> collects the number of serialization and deadlock

failures for each statement (notice that the total sum of per-command

failures of each type can be greater than the number of "transactions" with

these failures; see <xref linkend="transactions-and-scripts"

endterm="transactions-and-scripts-title"> for more information).

To get per-statement statistics, you can use the following options:

<itemizedlist>

<listitem>

<para>

<option>--report-latencies</> &mdash; collects the elapsed transaction

time of each statement and reports an average of those values, referred

to as the latency for each statement.

</para>

</listitem>

<listitem>

<para>

<option>--report-failures</> &mdash; collects the number of

serialization and deadlock failures for each statement.

</para>

<note>

<para>The total sum of per-command failures of each type can be greater

than the number of transactions with reported failures.

See <xref linkend="transactions-and-scripts"

endterm="transactions-and-scripts-title"> for more information.

</para>

</note>

</listitem>

</itemizedlist>

All values are computed for each statement executed by every client and are

reported after the benchmark has finished. You can use

<option>--report-latencies</> and <option>--report-failures</> options

together to get a full report.

</para>

<para>

For the default script if you use <option>-r</> option, the output will look

similar to this:

For the default script, if you usethe<option>-r</> option, the output will

looksimilar to this:

<screen>

starting vacuum...end.

transaction type: &lt;builtin: TPC-B (sort of)&gt;

</screen>

Another example of output for the default script using serializable default

transaction isolation level (-I S) and <option>--report-failures</> option:

transaction isolation level (<option>-I S</option>) and

<option>--report-failures</> option:

<screen>

starting vacuum...end.

transaction type: &lt;builtin: TPC-B (sort of)&gt;

- number of transactions with serialization failures: 9284 (92.840%)

- number of transactions with deadlock failures: 0 (0.000%)

- statement serialization and deadlock failures:

0 0 \set aid random(1, 100000 * :scale)

0 0 \set bid random(1, 1 * :scale)

0 0 \set tid random(1, 10 * :scale)

0 0 \set delta random(-5000, 5000)

0 0 BEGIN;

0 0 UPDATE pgbench_accounts SET abalance = abalance + :delta WHERE aid = :aid;

0 0 SELECT abalance FROM pgbench_accounts WHERE aid = :aid;

7975 0 UPDATE pgbench_tellers SET tbalance = tbalance + :delta WHERE tid = :tid;

1305 0 UPDATE pgbench_branches SET bbalance = bbalance + :delta WHERE bid = :bid;

0 0 INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES (:tid, :bid, :aid, :delta, CURRENT_TIMESTAMP);

4 0 END;

0 0 \set aid random(1, 100000 * :scale)

0 0 \set bid random(1, 1 * :scale)

0 0 \set tid random(1, 10 * :scale)

0 0 \set delta random(-5000, 5000)

0 0 BEGIN;

0 0 UPDATE pgbench_accounts

SET abalance = abalance + :delta WHERE aid = :aid;

0 0 SELECT abalance FROM pgbench_accounts

WHERE aid = :aid;

7975 0 UPDATE pgbench_tellers

SET tbalance = tbalance + :delta WHERE tid = :tid;

1305 0 UPDATE pgbench_branches

SET bbalance = bbalance + :delta WHERE bid = :bid;

0 0 INSERT INTO pgbench_history

(tid, bid, aid, delta, mtime)

VALUES (:tid, :bid, :aid, :delta, CURRENT_TIMESTAMP);

4 0 END;

</screen>

</para>