<replaceable>pattern</replaceable> is searched for
     in <replaceable>string</replaceable>, normally from the beginning of
     the string, but if the <replaceable>start</replaceable> parameter is
     provided then beginning from that character index.
     By default, only the first match of the pattern is replaced.
     If <replaceable>N</replaceable> is specified and is greater than zero,
     then the <replaceable>N</replaceable>'th match of the pattern
     is replaced.
     If the <literal>g</literal> flag is given, or
     if <replaceable>N</replaceable> is specified and is zero, then all
     matches at or after the <replaceable>start</replaceable> position are
     replaced.  (The <literal>g</literal> flag is ignored
     when <replaceable>N</replaceable> is specified.)
     The <replaceable>flags</replaceable> parameter is an optional text
     string containing zero or more single-letter flags that change the
     function's behavior.  Supported flags (though
     not <literal>g</literal>) are
     described in <xref linkend="posix-embedded-options-table"/>.
    </para>

   <para>
    Some examples:
<programlisting>
regexp_replace('foobarbaz', 'b..', 'X')
                                   <lineannotation>fooXbaz</lineannotation>
regexp_replace('foobarbaz', 'b..', 'X', 'g')
                                   <lineannotation>fooXX</lineannotation>
regexp_replace('foobarbaz', 'b(..)', 'X\1Y', 'g')
                                   <lineannotation>fooXarYXazY</lineannotation>
regexp_replace('A PostgreSQL function', 'a|e|i|o|u', 'X', 1, 0, 'i')
                                   <lineannotation>X PXstgrXSQL fXnctXXn</lineannotation>
regexp_replace(string=>'A PostgreSQL function', pattern=>'a|e|i|o|u', replacement=>'X', start=>1, "N"=>3, flags=>'i')
                                   <lineannotation>A PostgrXSQL function</lineannotation>
</programlisting>
   </para>

    <para>
     The <function>regexp_split_to_table</function> function splits a string using a POSIX
     regular expression pattern as a delimiter.  It has the syntax
     <function>regexp_split_to_table</function>(<replaceable>string</replaceable>, <replaceable>pattern</replaceable>
     <optional>, <replaceable>flags</replaceable> </optional>).
     If there is no match to the <replaceable>pattern</replaceable>, the function returns the
     <replaceable>string</replaceable>.  If there is at least one match, for each match it returns
     the text from the end of the last match (or the beginning of the string)
     to the beginning of the match.  When there are no more matches, it
     returns the text from the end of the last match to the end of the string.
     The <replaceable>flags</replaceable> parameter is an optional text string containing
     zero or more single-letter flags that change the function's behavior.
     <function>regexp_split_to_table</function> supports the flags described in
     <xref linkend="posix-embedded-options-table"/>.
    </para>

    <para>
     The <function>regexp_split_to_array</function> function behaves the same as
     <function>regexp_split_to_table</function>, except that <function>regexp_split_to_array</function>
     returns its result as an array of <type>text</type>.  It has the syntax
     <function>regexp_split_to_array</function>(<replaceable>string</replaceable>, <replaceable>pattern</replaceable>
     <optional>, <replaceable>flags</replaceable> </optional>).
     The parameters are the same as for <function>regexp_split_to_table</function>.
    </para>

   <para>
    Some examples:
<programlisting>
SELECT foo FROM regexp_split_to_table('the quick brown fox jumps over the lazy dog', '\s+') AS foo;
  foo
-------
 the
 quick
 brown
 fox
 jumps
 over
 the
 lazy
 dog
(9 rows)

SELECT regexp_split_to_array('the quick brown fox jumps over the lazy dog', '\s+');
              regexp_split_to_array
-----------------------------------------------
 {the,quick,brown,fox,jumps,over,the,lazy,dog}
(1 row)

SELECT foo