Mention paremeterized queries do not work with partial indexes.

Simon Riggs

diff --git a/doc/src/sgml/indices.sgml b/doc/src/sgml/indices.sgml
index 223bb81cfc8ebf84d8085ddca619ad84a2c251e3..5d4ecb6a2a120e133f040611213bcd1b50b03405 100644 (file)
--- a/doc/src/sgml/indices.sgml
+++ b/doc/src/sgml/indices.sgml
@@ -1,4 +1,4 @@
-
+
 
 
  Indexes
@@ -679,7 +679,12 @@ SELECT * FROM orders WHERE order_nr = 3501;
    x < 1 implies x < 2; otherwise
    the predicate condition must exactly match part of the query's
    WHERE condition
-   or the index will not be recognized to be usable.
+   or the index will not be recognized to be usable. Matching takes
+   place at query planning time, not at run time. As a result,
+   parameterized query clauses will not work with a partial index. For
+   example a prepared query with a parameter might specify 
+   x < ? which will never imply 
+   x < 2 for all possible values of the parameter.