Causes the duration of each completed statement to be logged

if the statement ran for at least the specified number of

milliseconds, modulated by <varname>log_statement_sample_rate</varname>.

Setting this to zero prints all statement durations. Minus-one (the default)

disables logging statement durations. For example, if you set it to

<literal>250ms</literal> then all SQL statements that run 250ms or longer

will be logged. Enabling this parameter can be helpful in tracking down

unoptimized queries in your applications.

Setting this to zero prints all statement durations.

<literal>-1</literal> (the default) disables logging statements due to

exceeding duration threshold; for example, if you set it to

<literal>250ms</literal>, then all SQL statements that run 250ms or

longer will be logged. Enabling this parameter can be helpful in

tracking down unoptimized queries in your applications.

Only superusers can change this setting.

</para>

</term>

<listitem>

<para>

Determines the fraction ofthestatements that exceed

<xref linkend="guc-log-min-duration-statement"/>whichtolog.

The default is <literal>1</literal>, meaning logtoall such

Determines the fraction of statements that exceed

<xref linkend="guc-log-min-duration-statement"/> tobe logged.

The default is <literal>1</literal>, meaning log all such

statements.

Setting this to zero disables logging, same as setting

<varname>log_min_duration_statement</varname>

to minus-one. <varname>log_statement_sample_rate</varname>

is helpful when the traffic is too high to log all queries.

Setting this to zero disables logging by duration, same as setting

<varname>log_min_duration_statement</varname> to

<literal>-1</literal>.

<varname>log_statement_sample_rate</varname> is helpful when the

traffic is too high to log all queries.

</para>

</listitem>

</varlistentry>

<note>

<para>

The difference betweensetting this option and setting

The difference betweenenabling <varname>log_duration</varname> and setting

<xref linkend="guc-log-min-duration-statement"/> to zero is that

exceeding <varname>log_min_duration_statement</varname> forces the text of

the query to be logged, but this option doesn't. Thus, if

{

{"log_statement_sample_rate",PGC_SUSET,LOGGING_WHEN,

gettext_noop("Fraction of statementsover log_min_duration_statement tolog."),

gettext_noop("If you only want a sample, use a value between 0 (never "

gettext_noop("Fraction of statementsexceeding log_min_duration_statement tobe logged."),

gettext_noop("If you only want a sample, use a value between 0.0 (never "

"log) and 1.0 (always log).")

},

&log_statement_sample_rate,

# 0 logs all statement, > 0 logs only statements running at

# least this number of milliseconds.

#log_statement_sample_rate = 1# Fraction of logged statementsover

# log_min_duration_statement. 1.0 logs all statements,

# 0 never logs.

#log_statement_sample_rate = 1.0# Fraction of logged statementsexceeding

# log_min_duration_statement to be logged.

#1.0 logs all such statements, 0.0 never logs.

#log_transaction_sample_rate = 0.0# Fraction of transactions whose statements

# are logged regardless of their duration. 1.0 logs all