Current File : //opt/alt/postgresql11/usr/share/doc/alt-postgresql11-9.2.24/html/runtime-config-developer.html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>Developer Options</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REV="MADE"
HREF="mailto:pgsql-docs@postgresql.org"><LINK
REL="HOME"
TITLE="PostgreSQL 9.2.24 Documentation"
HREF="index.html"><LINK
REL="UP"
TITLE="Server Configuration"
HREF="runtime-config.html"><LINK
REL="PREVIOUS"
TITLE="Customized Options"
HREF="runtime-config-custom.html"><LINK
REL="NEXT"
TITLE="Short Options"
HREF="runtime-config-short.html"><LINK
REL="STYLESHEET"
TYPE="text/css"
HREF="stylesheet.css"><META
HTTP-EQUIV="Content-Type"
CONTENT="text/html; charset=ISO-8859-1"><META
NAME="creation"
CONTENT="2017-11-06T22:43:11"></HEAD
><BODY
CLASS="SECT1"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="5"
ALIGN="center"
VALIGN="bottom"
><A
HREF="index.html"
>PostgreSQL 9.2.24 Documentation</A
></TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
TITLE="Customized Options"
HREF="runtime-config-custom.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
HREF="runtime-config.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="60%"
ALIGN="center"
VALIGN="bottom"
>Chapter 18. Server Configuration</TD
><TD
WIDTH="20%"
ALIGN="right"
VALIGN="top"
><A
TITLE="Short Options"
HREF="runtime-config-short.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="RUNTIME-CONFIG-DEVELOPER"
>18.17. Developer Options</A
></H1
><P
> The following parameters are intended for work on the
<SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> source code, and in some cases
to assist with recovery of severely damaged databases. There
should be no reason to use them on a production database.
As such, they have been excluded from the sample
<TT
CLASS="FILENAME"
>postgresql.conf</TT
> file. Note that many of these
parameters require special source compilation flags to work at all.
</P
><P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><A
NAME="GUC-ALLOW-SYSTEM-TABLE-MODS"
></A
><TT
CLASS="VARNAME"
>allow_system_table_mods</TT
> (<TT
CLASS="TYPE"
>boolean</TT
>)</DT
><DD
><P
> Allows modification of the structure of system tables.
This is used by <TT
CLASS="COMMAND"
>initdb</TT
>.
This parameter can only be set at server start.
</P
></DD
><DT
><A
NAME="GUC-DEBUG-ASSERTIONS"
></A
><TT
CLASS="VARNAME"
>debug_assertions</TT
> (<TT
CLASS="TYPE"
>boolean</TT
>)</DT
><DD
><P
> Turns on various assertion checks. This is a debugging aid. If
you are experiencing strange problems or crashes you might want
to turn this on, as it might expose programming mistakes. To use
this parameter, the macro <TT
CLASS="SYMBOL"
>USE_ASSERT_CHECKING</TT
>
must be defined when <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> is
built (accomplished by the <TT
CLASS="COMMAND"
>configure</TT
> option
<TT
CLASS="OPTION"
>--enable-cassert</TT
>). Note that
<TT
CLASS="VARNAME"
>debug_assertions</TT
> defaults to <TT
CLASS="LITERAL"
>on</TT
>
if <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> has been built with
assertions enabled.
</P
></DD
><DT
><A
NAME="GUC-IGNORE-SYSTEM-INDEXES"
></A
><TT
CLASS="VARNAME"
>ignore_system_indexes</TT
> (<TT
CLASS="TYPE"
>boolean</TT
>)</DT
><DD
><P
> Ignore system indexes when reading system tables (but still
update the indexes when modifying the tables). This is useful
when recovering from damaged system indexes.
This parameter cannot be changed after session start.
</P
></DD
><DT
><A
NAME="GUC-POST-AUTH-DELAY"
></A
><TT
CLASS="VARNAME"
>post_auth_delay</TT
> (<TT
CLASS="TYPE"
>integer</TT
>)</DT
><DD
><P
> If nonzero, a delay of this many seconds occurs when a new
server process is started, after it conducts the
authentication procedure. This is intended to give developers an
opportunity to attach to the server process with a debugger.
This parameter cannot be changed after session start.
</P
></DD
><DT
><A
NAME="GUC-PRE-AUTH-DELAY"
></A
><TT
CLASS="VARNAME"
>pre_auth_delay</TT
> (<TT
CLASS="TYPE"
>integer</TT
>)</DT
><DD
><P
> If nonzero, a delay of this many seconds occurs just after a
new server process is forked, before it conducts the
authentication procedure. This is intended to give developers an
opportunity to attach to the server process with a debugger to
trace down misbehavior in authentication.
This parameter can only be set in the <TT
CLASS="FILENAME"
>postgresql.conf</TT
>
file or on the server command line.
</P
></DD
><DT
><A
NAME="GUC-TRACE-NOTIFY"
></A
><TT
CLASS="VARNAME"
>trace_notify</TT
> (<TT
CLASS="TYPE"
>boolean</TT
>)</DT
><DD
><P
> Generates a great amount of debugging output for the
<TT
CLASS="COMMAND"
>LISTEN</TT
> and <TT
CLASS="COMMAND"
>NOTIFY</TT
>
commands. <A
HREF="runtime-config-logging.html#GUC-CLIENT-MIN-MESSAGES"
>client_min_messages</A
> or
<A
HREF="runtime-config-logging.html#GUC-LOG-MIN-MESSAGES"
>log_min_messages</A
> must be
<TT
CLASS="LITERAL"
>DEBUG1</TT
> or lower to send this output to the
client or server logs, respectively.
</P
></DD
><DT
><A
NAME="GUC-TRACE-RECOVERY-MESSAGES"
></A
><TT
CLASS="VARNAME"
>trace_recovery_messages</TT
> (<TT
CLASS="TYPE"
>enum</TT
>)</DT
><DD
><P
> Enables logging of recovery-related debugging output that otherwise
would not be logged. This parameter allows the user to override the
normal setting of <A
HREF="runtime-config-logging.html#GUC-LOG-MIN-MESSAGES"
>log_min_messages</A
>, but only for
specific messages. This is intended for use in debugging Hot Standby.
Valid values are <TT
CLASS="LITERAL"
>DEBUG5</TT
>, <TT
CLASS="LITERAL"
>DEBUG4</TT
>,
<TT
CLASS="LITERAL"
>DEBUG3</TT
>, <TT
CLASS="LITERAL"
>DEBUG2</TT
>, <TT
CLASS="LITERAL"
>DEBUG1</TT
>, and
<TT
CLASS="LITERAL"
>LOG</TT
>. The default, <TT
CLASS="LITERAL"
>LOG</TT
>, does not affect
logging decisions at all. The other values cause recovery-related
debug messages of that priority or higher to be logged as though they
had <TT
CLASS="LITERAL"
>LOG</TT
> priority; for common settings of
<TT
CLASS="VARNAME"
>log_min_messages</TT
> this results in unconditionally sending
them to the server log.
This parameter can only be set in the <TT
CLASS="FILENAME"
>postgresql.conf</TT
>
file or on the server command line.
</P
></DD
><DT
><A
NAME="GUC-TRACE-SORT"
></A
><TT
CLASS="VARNAME"
>trace_sort</TT
> (<TT
CLASS="TYPE"
>boolean</TT
>)</DT
><DD
><P
> If on, emit information about resource usage during sort operations.
This parameter is only available if the <TT
CLASS="SYMBOL"
>TRACE_SORT</TT
> macro
was defined when <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> was compiled.
(However, <TT
CLASS="SYMBOL"
>TRACE_SORT</TT
> is currently defined by default.)
</P
></DD
><DT
><TT
CLASS="VARNAME"
>trace_locks</TT
> (<TT
CLASS="TYPE"
>boolean</TT
>)</DT
><DD
><P
> If on, emit information about lock usage. Information dumped
includes the type of lock operation, the type of lock and the unique
identifier of the object being locked or unlocked. Also included
are bit masks for the lock types already granted on this object as
well as for the lock types awaited on this object. For each lock
type a count of the number of granted locks and waiting locks is
also dumped as well as the totals. An example of the log file output
is shown here:
</P><PRE
CLASS="SCREEN"
>LOG: LockAcquire: new: lock(0xb7acd844) id(24688,24696,0,0,0,1)
grantMask(0) req(0,0,0,0,0,0,0)=0 grant(0,0,0,0,0,0,0)=0
wait(0) type(AccessShareLock)
LOG: GrantLock: lock(0xb7acd844) id(24688,24696,0,0,0,1)
grantMask(2) req(1,0,0,0,0,0,0)=1 grant(1,0,0,0,0,0,0)=1
wait(0) type(AccessShareLock)
LOG: UnGrantLock: updated: lock(0xb7acd844) id(24688,24696,0,0,0,1)
grantMask(0) req(0,0,0,0,0,0,0)=0 grant(0,0,0,0,0,0,0)=0
wait(0) type(AccessShareLock)
LOG: CleanUpLock: deleting: lock(0xb7acd844) id(24688,24696,0,0,0,1)
grantMask(0) req(0,0,0,0,0,0,0)=0 grant(0,0,0,0,0,0,0)=0
wait(0) type(INVALID)</PRE
><P>
Details of the structure being dumped may be found in
<TT
CLASS="FILENAME"
>src/include/storage/lock.h</TT
>.
</P
><P
> This parameter is only available if the <TT
CLASS="SYMBOL"
>LOCK_DEBUG</TT
>
macro was defined when <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> was
compiled.
</P
></DD
><DT
><TT
CLASS="VARNAME"
>trace_lwlocks</TT
> (<TT
CLASS="TYPE"
>boolean</TT
>)</DT
><DD
><P
> If on, emit information about lightweight lock usage. Lightweight
locks are intended primarily to provide mutual exclusion of access
to shared-memory data structures.
</P
><P
> This parameter is only available if the <TT
CLASS="SYMBOL"
>LOCK_DEBUG</TT
>
macro was defined when <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> was
compiled.
</P
></DD
><DT
><TT
CLASS="VARNAME"
>trace_userlocks</TT
> (<TT
CLASS="TYPE"
>boolean</TT
>)</DT
><DD
><P
> If on, emit information about user lock usage. Output is the same
as for <TT
CLASS="SYMBOL"
>trace_locks</TT
>, only for advisory locks.
</P
><P
> This parameter is only available if the <TT
CLASS="SYMBOL"
>LOCK_DEBUG</TT
>
macro was defined when <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> was
compiled.
</P
></DD
><DT
><TT
CLASS="VARNAME"
>trace_lock_oidmin</TT
> (<TT
CLASS="TYPE"
>integer</TT
>)</DT
><DD
><P
> If set, do not trace locks for tables below this OID. (use to avoid
output on system tables)
</P
><P
> This parameter is only available if the <TT
CLASS="SYMBOL"
>LOCK_DEBUG</TT
>
macro was defined when <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> was
compiled.
</P
></DD
><DT
><TT
CLASS="VARNAME"
>trace_lock_table</TT
> (<TT
CLASS="TYPE"
>integer</TT
>)</DT
><DD
><P
> Unconditionally trace locks on this table (OID).
</P
><P
> This parameter is only available if the <TT
CLASS="SYMBOL"
>LOCK_DEBUG</TT
>
macro was defined when <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> was
compiled.
</P
></DD
><DT
><TT
CLASS="VARNAME"
>debug_deadlocks</TT
> (<TT
CLASS="TYPE"
>boolean</TT
>)</DT
><DD
><P
> If set, dumps information about all current locks when a
deadlock timeout occurs.
</P
><P
> This parameter is only available if the <TT
CLASS="SYMBOL"
>LOCK_DEBUG</TT
>
macro was defined when <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> was
compiled.
</P
></DD
><DT
><TT
CLASS="VARNAME"
>log_btree_build_stats</TT
> (<TT
CLASS="TYPE"
>boolean</TT
>)</DT
><DD
><P
> If set, logs system resource usage statistics (memory and CPU) on
various B-tree operations.
</P
><P
> This parameter is only available if the <TT
CLASS="SYMBOL"
>BTREE_BUILD_STATS</TT
>
macro was defined when <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> was
compiled.
</P
></DD
><DT
><A
NAME="GUC-WAL-DEBUG"
></A
><TT
CLASS="VARNAME"
>wal_debug</TT
> (<TT
CLASS="TYPE"
>boolean</TT
>)</DT
><DD
><P
> If on, emit WAL-related debugging output. This parameter is
only available if the <TT
CLASS="SYMBOL"
>WAL_DEBUG</TT
> macro was
defined when <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> was
compiled.
</P
></DD
><DT
><A
NAME="GUC-ZERO-DAMAGED-PAGES"
></A
><TT
CLASS="VARNAME"
>zero_damaged_pages</TT
> (<TT
CLASS="TYPE"
>boolean</TT
>)</DT
><DD
><P
> Detection of a damaged page header normally causes
<SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> to report an error, aborting the current
transaction. Setting <TT
CLASS="VARNAME"
>zero_damaged_pages</TT
> to on causes
the system to instead report a warning, zero out the damaged
page in memory, and continue processing. This behavior <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>will destroy data</I
></SPAN
>,
namely all the rows on the damaged page. However, it does allow you to get
past the error and retrieve rows from any undamaged pages that might
be present in the table. It is useful for recovering data if
corruption has occurred due to a hardware or software error. You should
generally not set this on until you have given up hope of recovering
data from the damaged pages of a table. Zeroed-out pages are not
forced to disk so it is recommended to recreate the table or
the index before turning this parameter off again. The
default setting is <TT
CLASS="LITERAL"
>off</TT
>, and it can only be changed
by a superuser.
</P
></DD
></DL
></DIV
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="runtime-config-custom.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="runtime-config-short.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>Customized Options</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="runtime-config.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>Short Options</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>
Mini Shell