On Thu, May 2, 2019 at 1:03 AM Arthur Zakirov <a.zaki...@postgrespro.ru> wrote:
> On Thu, May 2, 2019 at 12:49 AM Alexander Korotkov
> <a.korot...@postgrespro.ru> wrote:
> > Actually, FX takes effect on subsequent format patterns. This is not
> > documented, but it copycats Oracle behavior. Sure, normally FX should
> > be specified as the first item. We could document current behavior or
> > restrict specifying FX not as first item. This is also not new in 12,
> > so documenting current behavior is better for compatibility.
>
> I went to Oracle's documentation. It seems that the behavior is
> slightly different.
> Their documentation says:
>
> "A modifier can appear in a format model more than once. In such a case,
> each subsequent occurrence toggles the effects of the modifier. Its effects
> are
> enabled for the portion of the model following its first occurrence, and then
> disabled for the portion following its second, and then reenabled for
> the portion
> following its third, and so on."
What about the patch I attached? It fixes the explanation of FX option a little.
--
Arthur Zakirov
Postgres Professional: http://www.postgrespro.com
Russian Postgres Company
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index d751766004..118da982ee 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -6381,8 +6381,10 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
<literal>to_timestamp('2000 - JUN', 'YYYY-MON')</literal> work, but
<literal>to_timestamp('2000 JUN', 'FXYYYY MON')</literal> returns an error
because <function>to_timestamp</function> expects only a single space.
- <literal>FX</literal> must be specified as the first item in
- the template.
+ <literal>FX</literal> option occurrence enables exact matching mode for
+ the remaining input string. It can appear in a template string more than
+ once, but multiple occurrences don't make sense because each of them
+ doesn't toggle exact matching mode.
</para>
</listitem>
