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<sect1 id="bug-reporting">
 <title>Bug Reporting Guidelines</title>

 <para>
  When you find a bug in <productname>PostgreSQL</productname> we want to
  hear about it. Your bug reports play an important part in making
  <productname>PostgreSQL</productname> more reliable because even the utmost
  care cannot guarantee that every part of
  <productname>PostgreSQL</productname>
  will work on every platform under every circumstance.
 </para>

 <para>
  The following suggestions are intended to assist you in forming bug reports
  that can be handled in an effective fashion. No one is required to follow
  them but doing so tends to be to everyone's advantage.
 </para>

 <para>
  We cannot promise to fix every bug right away. If the bug is obvious, critical,
  or affects a lot of users, chances are good that someone will look into it. It
  could also happen that we tell you to update to a newer version to see if the
  bug happens there. Or we might decide that the bug
  cannot be fixed before some major rewrite we might be planning is done. Or
  perhaps it is simply too hard and there are more important things on the agenda.
  If you need help immediately, consider obtaining a commercial support contract.
 </para>

 <sect2>
  <title>Identifying Bugs</title>

  <para>
   Before you report a bug, please read and re-read the
   documentation to verify that you can really do whatever it is you are
   trying. If it is not clear from the documentation whether you can do
   something or not, please report that too; it is a bug in the documentation.
   If it turns out that a program does something different from what the
   documentation says, that is a bug. That might include, but is not limited to,
   the following circumstances:

   <itemizedlist>
    <listitem>
     <para>
      A program terminates with a fatal signal or an operating system
      error message that would point to a problem in the program. (A
      counterexample might be a <quote>disk full</quote> message,
      since you have to fix that yourself.)
     </para>
    </listitem>

    <listitem>
     <para>
      A program produces the wrong output for any given input.
     </para>
    </listitem>

    <listitem>
     <para>
      A program refuses to accept valid input (as defined in the documentation).
     </para>
    </listitem>

    <listitem>
     <para>
      A program accepts invalid input without a notice or error message.
      But keep in mind that your idea of invalid input might be our idea of
      an extension or compatibility with traditional practice.
     </para>
    </listitem>

    <listitem>
     <para>
      <productname>PostgreSQL</productname> fails to compile, build, or
      install according to the instructions on supported platforms.
     </para>
    </listitem>
   </itemizedlist>

   Here <quote>program</quote> refers to any executable, not only the backend process.
  </para>

  <para>
   Being slow or resource-hogging is not necessarily a bug. Read the
   documentation or ask on one of the mailing lists for help in tuning your
   applications. Failing to comply to the <acronym>SQL</acronym> standard is
   not necessarily a bug either, unless compliance for the
   specific feature is explicitly claimed.
  </para>

  <para>
   Before you continue, check on the TODO list and in the FAQ to see if your bug is
   already known. If you cannot decode the information on the TODO list, report your
   problem. The least we can do is make the TODO list clearer.
  </para>
 </sect2>

 <sect2>
  <title>What to Report</title>

  <para>
   The most important thing to remember about bug reporting is to state all
   the facts and only facts. Do not speculate what you think went wrong, what
   <quote>it seemed to do</quote>, or which part of the program has a fault.
   If you are not familiar with the implementation you would probably guess
   wrong and not help us a bit. And even if you are, educated explanations are
   a great supplement to but no substitute for facts. If we are going to fix
   the bug we still have to see it happen for ourselves first.
   Reporting the bare facts
   is relatively straightforward (you can probably copy and paste them from the
   screen) but all too often important details are left out because someone
   thought it does not matter or the report would be understood
   anyway.
  </para>

  <para>
   The following items should be contained in every bug report:

   <itemizedlist>
    <listitem>
     <para>
      The exact sequence of steps <emphasis>from program
      start-up</emphasis> necessary to reproduce the problem. This
      should be self-contained; it is not enough to send in a bare
      <command>SELECT</command> statement without the preceding
      <command>CREATE TABLE</command> and <command>INSERT</command>
      statements, if the output should depend on the data in the
      tables. We do not have the time to reverse-engineer your
      database schema, and if we are supposed to make up our own data
      we would probably miss the problem.
     </para>

     <para>
      The best format for a test case for SQL-related problems is a
      file that can be run through the <application>psql</application>
      frontend that shows the problem. (Be sure to not have anything
      in your <filename>~/.psqlrc</filename> start-up file.)  An easy
      way to create this file is to use <application>pg_dump</application>
      to dump out the table declarations and data needed to set the
      scene, then add the problem query.  You are encouraged to
      minimize the size of your example, but this is not absolutely
      necessary.  If the bug is reproducible, we will find it either
      way.
     </para>

     <para>
      If your application uses some other client interface, such as <application>PHP</application>, then
      please try to isolate the offending queries. We will probably not set up a
      web server to reproduce your problem. In any case remember to provide
      the exact input files; do not guess that the problem happens for
      <quote>large files</quote> or <quote>midsize databases</quote>, etc. since this
      information is too inexact to be of use.
     </para>
    </listitem>

    <listitem>
     <para>
      The output you got. Please do not say that it <quote>didn't work</quote> or
      <quote>crashed</quote>. If there is an error message,
      show it, even if you do not understand it. If the program terminates with
      an operating system error, say which. If nothing at all happens, say so.
      Even if the result of your test case is a program crash or otherwise obvious
      it might not happen on our platform. The easiest thing is to copy the output
      from the terminal, if possible.
     </para>
     <note>
      <para>
       If you are reporting an error message, please obtain the most verbose
       form of the message.  In <application>psql</application>, say <literal>\set
       VERBOSITY verbose</literal> beforehand.  If you are extracting the message
       from the server log, set the run-time parameter
       <xref linkend="guc-log-error-verbosity"/> to <literal>verbose</literal> so that all
       details are logged.
      </para>
     </note>
     <note>
      <para>
       In case of fatal errors, the error message reported by the client might
       not contain all the information available. Please also look at the
       log output of the database server. If you do not keep your server's log
       output, this would be a good time to start doing so.
      </para>
     </note>
    </listitem>

    <listitem>
     <para>
      The output you expected is very important to state. If you just write
      <quote>This command gives me that output.</quote> or <quote>This is not
      what I expected.</quote>, we might run it ourselves, scan the output, and
      think it looks OK and is exactly what we expected. We should not have to
      spend the time to decode the exact semantics behind your commands.
      Especially refrain from merely saying that <quote>This is not what SQL says/Oracle
      does.</quote> Digging out the correct behavior from <acronym>SQL</acronym>
      is not a fun undertaking, nor do we all know how all the other relational
      databases out there behave. (If your problem is a program crash, you can
      obviously omit this item.)
     </para>
    </listitem>

    <listitem>
     <para>
      Any command line options and other start-up options, including
      any relevant environment variables or configuration files that
      you changed from the default. Again, please provide exact
      information. If you are using a prepackaged distribution that
      starts the database server at boot time, you should try to find
      out how that is done.
     </para>
    </listitem>

    <listitem>
     <para>
      Anything you did at all differently from the installation
      instructions.
     </para>
    </listitem>

    <listitem>
     <para>
      The <productname>PostgreSQL</productname> version. You can run the command
      <literal>SELECT version();</literal> to
      find out the version of the server you are connected to.  Most executable
      programs also support a <option>--version</option> option; at least
      <literal>postgres --version</literal> and <literal>psql --version</literal>
      should work.
      If the function or the options do not exist then your version is
      more than old enough to warrant an upgrade.
      If you run a prepackaged version, such as RPMs, say so, including any
      subversion the package might have. If you are talking about a Git
      snapshot, mention that, including the commit hash.
     </para>

     <para>
      If your version is older than &version; we will almost certainly
      tell you to upgrade. There are many bug fixes and improvements
      in each new release, so it is quite possible that a bug you have
      encountered in an older release of <productname>PostgreSQL</productname>
      has already been fixed. We can only provide limited support for
      sites using older releases of <productname>PostgreSQL</productname>; if you
      require more than we can provide, consider acquiring a
      commercial support contract.
     </para>
     <para>
     </para>
    </listitem>

    <listitem>
     <para>
      Platform information. This includes the kernel name and version,
      C library, processor, memory information, and so on. In most
      cases it is sufficient to report the vendor and version, but do
      not assume everyone knows what exactly <quote>Debian</quote>
      contains or that everyone runs on x86_64. If you have
      installation problems then information about the toolchain on
      your machine (compiler, <application>make</application>, and so
      on) is also necessary.
     </para>
    </listitem>
   </itemizedlist>

   Do not be afraid if your bug report becomes rather lengthy. That is a fact of life.
   It is better to report everything the first time than us having to squeeze the
   facts out of you. On the other hand, if your input files are huge, it is
   fair to ask first whether somebody is interested in looking into it.  Here is
   an <ulink url="https://www.chiark.greenend.org.uk/~sgtatham/bugs.html">article</ulink>
   that outlines some more tips on reporting bugs.
  </para>

  <para>
   Do not spend all your time to figure out which changes in the input make
   the problem go away. This will probably not help solving it. If it turns
   out that the bug cannot be fixed right away, you will still have time to
   find and share your work-around. Also, once again, do not waste your time
   guessing why the bug exists. We will find that out soon enough.
  </para>

  <para>
   When writing a bug report, please avoid confusing terminology.
   The software package in total is called <quote>PostgreSQL</quote>,
   sometimes <quote>Postgres</quote> for short. If you
   are specifically talking about the backend process, mention that, do not
   just say <quote>PostgreSQL crashes</quote>.  A crash of a single
   backend process is quite different from crash of the parent
   <quote>postgres</quote> process; please don't say <quote>the server
   crashed</quote> when you mean a single backend process went down, nor vice versa.
   Also, client programs such as the interactive frontend <quote><application>psql</application></quote>
   are completely separate from the backend.  Please try to be specific
   about whether the problem is on the client or server side.
  </para>
 </sect2>

 <sect2>
  <title>Where to Report Bugs</title>

  <para>
   In general, send bug reports to the bug report mailing list at
   <email>pgsql-bugs@lists.postgresql.org</email>.
   You are requested to use a descriptive subject for your email
   message, perhaps parts of the error message.
  </para>

  <para>
   Another method is to fill in the bug report web-form available
   at the project's
   <ulink url="https://www.postgresql.org/">web site</ulink>.
   Entering a bug report this way causes it to be mailed to the
   <email>pgsql-bugs@lists.postgresql.org</email> mailing list.
  </para>

  <para>
   If your bug report has security implications and you'd prefer that it
   not become immediately visible in public archives, don't send it to
   <literal>pgsql-bugs</literal>.  Security issues can be
   reported privately to <email>security@postgresql.org</email>.
  </para>

  <para>
   Do not send bug reports to any of the user mailing lists, such as
   <email>pgsql-sql@lists.postgresql.org</email> or
   <email>pgsql-general@lists.postgresql.org</email>.
   These mailing lists are for answering
   user questions, and their subscribers normally do not wish to receive
   bug reports. More importantly, they are unlikely to fix them.
  </para>

  <para>
   Also, please do <emphasis>not</emphasis> send reports to
   the developers' mailing list <email>pgsql-hackers@lists.postgresql.org</email>.
   This list is for discussing the
   development of <productname>PostgreSQL</productname>, and it would be nice
   if we could keep the bug reports separate. We might choose to take up a
   discussion about your bug report on <literal>pgsql-hackers</literal>,
   if the problem needs more review.
  </para>

  <para>
   If you have a problem with the documentation, the best place to report it
   is the documentation mailing list <email>pgsql-docs@lists.postgresql.org</email>.
   Please be specific about what part of the documentation you are unhappy
   with.
  </para>

  <para>
   If your bug is a portability problem on a non-supported platform,
   send mail to <email>pgsql-hackers@lists.postgresql.org</email>,
   so we (and you) can work on
   porting <productname>PostgreSQL</productname> to your platform.
  </para>

  <note>
   <para>
    Due to the unfortunate amount of spam going around, all of the above
    lists will be moderated unless you are subscribed. That means there
    will be some delay before the email is delivered. If you wish to subscribe
    to the lists, please visit
    <ulink url="https://lists.postgresql.org/"></ulink> for instructions.
   </para>
  </note>
 </sect2>
</sect1>
