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1 | 1 | <!-- |
2 | | -$PostgreSQL: pgsql/doc/src/sgml/xfunc.sgml,v 1.109 2005/11/29 01:46:54 alvherre Exp $ |
| 2 | +$PostgreSQL: pgsql/doc/src/sgml/xfunc.sgml,v 1.110 2006/01/19 22:52:08 momjian Exp $ |
3 | 3 | --> |
4 | 4 |
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5 | 5 | <sect1 id="xfunc"> |
@@ -899,13 +899,13 @@ CREATE FUNCTION test(int, int) RETURNS int |
899 | 899 | <para> |
900 | 900 | A <literal>STABLE</> function cannot modify the database and is |
901 | 901 | guaranteed to return the same results given the same arguments |
902 | | - for allcalls within a singlesurrounding query.This category |
903 | | -allows theoptimizer to optimizeawaymultiple calls of the function |
904 | | -within a single query.In particular, it is safe to use an expression |
905 | | -containingsuch a function in an index scan condition.(Since an |
906 | | -index scanwill evaluate the comparison value only once, not once at |
907 | | -eachrow, it is not valid to use a <literal>VOLATILE</> function in |
908 | | -anindex scan condition.) |
| 902 | + for allrows within a singlestatement.This category allows the |
| 903 | + optimizer to optimize multiple calls of the function to a single |
| 904 | +call.In particular, it is safe to use an expression containing |
| 905 | + such a function in an index scan condition. (Since an index scan |
| 906 | + will evaluate the comparison value only once, not once at each |
| 907 | + row, it is not valid to use a <literal>VOLATILE</> function in an |
| 908 | + index scan condition.) |
909 | 909 | </para> |
910 | 910 | </listitem> |
911 | 911 | <listitem> |
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