Doc: copy-editing for debug_invalidate_system_caches_always description.

I came to fix "useful only useful", but the more I looked at the text
the more things I thought could be improved.
This commit is contained in:
Tom Lane 2021-05-08 11:33:13 -04:00
parent 9681f2160d
commit f9b809e7fb
1 changed files with 10 additions and 9 deletions

View File

@ -10406,28 +10406,29 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
</term>
<listitem>
<para>
When set to 1, each cache lookup for a system catalog entry is
invalidated at the first possible opportunity, irrespective of whether
When set to <literal>1</literal>, each system catalog cache entry is
invalidated at the first possible opportunity, whether or not
anything that would render it invalid really occurred. Caching of
system catalogs is effectively disabled as a result, so the server
will run extremely slowly. Higher values run the cache invalidation
recursively, which is even slower and useful only useful for testing
in very specific scenarios.
recursively, which is even slower and only useful for testing
the caching logic itself. The default value of <literal>0</literal>
selects normal catalog caching behavior.
</para>
<para>
This option can be very helpful when trying to trigger
hard-to-reproduce bugs involving concurrency and catalog changes but
This parameter can be very helpful when trying to trigger
hard-to-reproduce bugs involving concurrent catalog changes, but it
is otherwise rarely needed. See the source code files
<filename>inval.c</filename> and
<filename>pg_config_manual.h</filename> for details.
</para>
<para>
This setting is supported but off by default (0) when
<symbol>CLOBBER_CACHE_ENABLED</symbol> is defined at compile time
This parameter is supported when
<symbol>CLOBBER_CACHE_ENABLED</symbol> was defined at compile time
(which happens automatically when using the
<literal>configure</literal> option
<application>configure</application> option
<option>--enable-cassert</option>). In production builds, its value
will always be <literal>0</literal> and attempts to set it to another
value will raise an error.