提交 c0a92837 编写于 作者: P Peter Eisentraut

Rename collect_* options to more user-friendly names.

上级 9e60c0f6
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/runtime.sgml,v 1.84 2001/09/21 20:31:43 tgl Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/runtime.sgml,v 1.85 2001/09/23 21:52:36 petere Exp $
-->
<Chapter Id="runtime">
......@@ -780,45 +780,6 @@ env PGOPTIONS='-c geqo=off' psql
<para>
<variablelist>
<varlistentry>
<term><varname>COLLECT_STARTCOLLECTOR</varname> (<type>boolean</type>)</term>
<listitem>
<para>
Controls whether the postmaster should start the statistics-collection
subprocess. This is on by default, but may be turned off if you
know you have no interest in collecting statistics. This option
can only be set at postmaster start.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>COLLECT_RESETONPMSTART</varname> (<type>boolean</type>)</term>
<listitem>
<para>
If on, collected statistics are zeroed out whenever the postmaster
is restarted. If off, statistics are accumulated across postmaster
restarts. The default is on. This option
can only be set at postmaster start.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>COLLECT_QUERYSTRING</varname> (<type>boolean</type>)</term>
<term><varname>COLLECT_BLOCKLEVEL</varname> (<type>boolean</type>)</term>
<term><varname>COLLECT_TUPLELEVEL</varname> (<type>boolean</type>)</term>
<listitem>
<para>
These flags determine what information backends send to the statistics
collector process: current queries, block-level activity statistics,
or tuple-level activity statistics. All default to off. Enabling
statistics collection costs a small amount of time per query, but
is invaluable for debugging and performance tuning.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>DEBUG_ASSERTIONS</varname> (<type>boolean</type>)</term>
<listitem>
......@@ -940,6 +901,45 @@ env PGOPTIONS='-c geqo=off' psql
</listitem>
</varlistentry>
<varlistentry>
<term><varname>STATS_COMMAND_STRING</varname> (<type>boolean</type>)</term>
<term><varname>STATS_BLOCK_LEVEL</varname> (<type>boolean</type>)</term>
<term><varname>STATS_ROW_LEVEL</varname> (<type>boolean</type>)</term>
<listitem>
<para>
These flags determine what information backends send to the statistics
collector process: current commands, block-level activity statistics,
or row-level activity statistics. All default to off. Enabling
statistics collection costs a small amount of time per query, but
is invaluable for debugging and performance tuning.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>STATS_RESET_ON_SERVER_START</varname> (<type>boolean</type>)</term>
<listitem>
<para>
If on, collected statistics are zeroed out whenever the server
is restarted. If off, statistics are accumulated across server
restarts. The default is on. This option
can only be set at server start.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>STATS_START_COLLECTOR</varname> (<type>boolean</type>)</term>
<listitem>
<para>
Controls whether the server should start the statistics-collection
subprocess. This is on by default, but may be turned off if you
know you have no interest in collecting statistics. This option
can only be set at server start.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>SYSLOG</varname> (<type>integer</type>)</term>
<listitem>
......@@ -1268,49 +1268,6 @@ dynamic_library_path = '/usr/local/lib/postgresql:/home/my_project/lib:$libdir'
</listitem>
</varlistentry>
<varlistentry>
<term><varname>TRANSFORM_NULL_EQUALS</varname> (<type>boolean</type>)</term>
<listitem>
<para>
When turned on, expressions of the form
<literal><replaceable>expr</> = NULL</literal> (or
<literal>NULL = <replaceable>expr</></literal>) are treated as
<literal><replaceable>expr</> IS NULL</literal>, that is, they
return true if <replaceable>expr</> evaluates to the NULL
value, and false otherwise. The correct behavior of
<literal><replaceable>expr</> = NULL</literal> is to always
return NULL (unknown). Therefore this option defaults to off.
</para>
<para>
However, filtered forms in <productname>Microsoft
Access</productname> generate queries that appear to use
<literal><replaceable>expr</> = NULL</literal> to test for
NULLs, so if you use that interface to access the database you
might want to turn this option on. Since expressions of the
form <literal><replaceable>expr</> = NULL</literal> always
return NULL (using the correct interpretation) they are not
very useful and do not appear often in normal applications, so
this option does little harm in practice. But new users are
frequently confused about the semantics of expressions
involving NULL, so we do not turn this option on by default.
</para>
<para>
Note that this option only affects the literal <literal>=</>
operator, not other comparison operators or other expressions
that are computationally equivalent to some expression
involving the equals operator (such as <literal>IN</literal>).
Thus, this option is not a general fix for bad programming.
</para>
<para>
Refer to the <citetitle>User's Guide</citetitle> for related
information.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>PORT</varname> (<type>integer</type>)</term>
<listitem>
......@@ -1408,6 +1365,49 @@ dynamic_library_path = '/usr/local/lib/postgresql:/home/my_project/lib:$libdir'
</listitem>
</varlistentry>
<varlistentry>
<term><varname>TRANSFORM_NULL_EQUALS</varname> (<type>boolean</type>)</term>
<listitem>
<para>
When turned on, expressions of the form
<literal><replaceable>expr</> = NULL</literal> (or
<literal>NULL = <replaceable>expr</></literal>) are treated as
<literal><replaceable>expr</> IS NULL</literal>, that is, they
return true if <replaceable>expr</> evaluates to the NULL
value, and false otherwise. The correct behavior of
<literal><replaceable>expr</> = NULL</literal> is to always
return NULL (unknown). Therefore this option defaults to off.
</para>
<para>
However, filtered forms in <productname>Microsoft
Access</productname> generate queries that appear to use
<literal><replaceable>expr</> = NULL</literal> to test for
NULLs, so if you use that interface to access the database you
might want to turn this option on. Since expressions of the
form <literal><replaceable>expr</> = NULL</literal> always
return NULL (using the correct interpretation) they are not
very useful and do not appear often in normal applications, so
this option does little harm in practice. But new users are
frequently confused about the semantics of expressions
involving NULL, so we do not turn this option on by default.
</para>
<para>
Note that this option only affects the literal <literal>=</>
operator, not other comparison operators or other expressions
that are computationally equivalent to some expression
involving the equals operator (such as <literal>IN</literal>).
Thus, this option is not a general fix for bad programming.
</para>
<para>
Refer to the <citetitle>User's Guide</citetitle> for related
information.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>UNIX_SOCKET_DIRECTORY</varname> (<type>string</type>)</term>
<listitem>
......
......@@ -4,7 +4,7 @@
* Support for grand unified configuration scheme, including SET
* command, configuration file, and command line options.
*
* $Header: /cvsroot/pgsql/src/backend/utils/misc/guc.c,v 1.51 2001/09/21 17:06:12 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/utils/misc/guc.c,v 1.52 2001/09/23 21:52:36 petere Exp $
*
* Copyright 2000 by PostgreSQL Global Development Group
* Written by Peter Eisentraut <peter_e@gmx.net>.
......@@ -229,11 +229,11 @@ static struct config_bool
{"show_btree_build_stats", PGC_SUSET, &Show_btree_build_stats, false, NULL},
#endif
{"collect_startcollector", PGC_POSTMASTER, &pgstat_collect_startcollector, true, NULL},
{"collect_resetonpmstart", PGC_POSTMASTER, &pgstat_collect_resetonpmstart, true, NULL},
{"collect_querystring", PGC_SUSET, &pgstat_collect_querystring, false, NULL},
{"collect_tuplelevel", PGC_SUSET, &pgstat_collect_tuplelevel, false, NULL},
{"collect_blocklevel", PGC_SUSET, &pgstat_collect_blocklevel, false, NULL},
{"stats_start_collector", PGC_POSTMASTER, &pgstat_collect_startcollector, true, NULL},
{"stats_reset_on_server_start", PGC_POSTMASTER, &pgstat_collect_resetonpmstart, true, NULL},
{"stats_command_string", PGC_SUSET, &pgstat_collect_querystring, false, NULL},
{"stats_row_level", PGC_SUSET, &pgstat_collect_tuplelevel, false, NULL},
{"stats_block_level", PGC_SUSET, &pgstat_collect_blocklevel, false, NULL},
{"trace_notify", PGC_USERSET, &Trace_notify, false, NULL},
......
......@@ -150,11 +150,11 @@
#
# Access statistics collection
#
#collect_startcollector = true
#collect_resetonpmstart = true
#collect_querystring = false
#collect_tuplelevel = false
#collect_blocklevel = false
#stats_start_collector = true
#stats_reset_on_server_start = true
#stats_command_string = false
#stats_row_level = false
#stats_block_level = false
#
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册