probes available
   in <productname>PostgreSQL</productname>. To include DTrace support
   specify <option>--enable-dtrace</option> to configure.  See <xref
   linkend="configure-options-devel"/> for further information.
  </para>
  </sect2>

  <sect2 id="trace-points">
   <title>Built-in Probes</title>

  <para>
   A number of standard probes are provided in the source code,
   as shown in <xref linkend="dtrace-probe-point-table"/>;
   <xref linkend="typedefs-table"/>
   shows the types used in the probes.  More probes can certainly be
   added to enhance <productname>PostgreSQL</productname>'s observability.
  </para>

 <table id="dtrace-probe-point-table">
  <title>Built-in DTrace Probes</title>
  <tgroup cols="3">
   <colspec colname="col1" colwidth="2*"/>
   <colspec colname="col2" colwidth="3*"/>
   <colspec colname="col3" colwidth="3*"/>
   <thead>
    <row>
     <entry>Name</entry>
     <entry>Parameters</entry>
     <entry>Description</entry>
    </row>
   </thead>

   <tbody>

    <row>
     <entry><literal>transaction-start</literal></entry>
     <entry><literal>(LocalTransactionId)</literal></entry>
     <entry>Probe that fires at the start of a new transaction.
      arg0 is the transaction ID.</entry>
    </row>
    <row>
     <entry><literal>transaction-commit</literal></entry>
     <entry><literal>(LocalTransactionId)</literal></entry>
     <entry>Probe that fires when a transaction completes successfully.
      arg0 is the transaction ID.</entry>
    </row>
    <row>
     <entry><literal>transaction-abort</literal></entry>
     <entry><literal>(LocalTransactionId)</literal></entry>
     <entry>Probe that fires when a transaction completes unsuccessfully.
      arg0 is the transaction ID.</entry>
    </row>
    <row>
     <entry><literal>query-start</literal></entry>
     <entry><literal>(const char *)</literal></entry>
     <entry>Probe that fires when the processing of a query is started.
      arg0 is the query string.</entry>
    </row>
    <row>
     <entry><literal>query-done</literal></entry>
     <entry><literal>(const char *)</literal></entry>
     <entry>Probe that fires when the processing of a query is complete.
      arg0 is the query string.</entry>
    </row>
    <row>
     <entry><literal>query-parse-start</literal></entry>
     <entry><literal>(const char *)</literal></entry>
     <entry>Probe that fires when the parsing of a query is started.
      arg0 is the query string.</entry>
    </row>
    <row>
     <entry><literal>query-parse-done</literal></entry>
     <entry><literal>(const char *)</literal></entry>
     <entry>Probe that fires when the parsing of a query is complete.
      arg0 is the query string.</entry>
    </row>
    <row>
     <entry><literal>query-rewrite-start</literal></entry>
     <entry><literal>(const char *)</literal></entry>
     <entry>Probe that fires when the rewriting of a query is started.
      arg0 is the query string.</entry>
    </row>
    <row>
     <entry><literal>query-rewrite-done</literal></entry>
     <entry><literal>(const char *)</literal></entry>
     <entry>Probe that fires when the rewriting of a query is complete.
      arg0 is the query string.</entry>
    </row>
    <row>
     <entry><literal>query-plan-start</literal></entry>
     <entry><literal>()</literal></entry>
     <entry>Probe that fires when the planning of a query is started.</entry>
    </row>
    <row>
     <entry><literal>query-plan-done</literal></entry>
     <entry><literal>()</literal></entry>
     <entry>Probe that fires when the planning of a query is complete.</entry>
    </row>
    <row>
     <entry><literal>query-execute-start</literal></entry>
     <entry><literal>()</literal></entry>
     <entry>Probe that fires when the execution of a query is started.</entry>
    </row>
    <row>
     <entry><literal>query-execute-done</literal></entry>
     <entry><literal>()</literal></entry>
     <entry>Probe that fires when the execution of a query is complete.</entry>
    </row>