Update FDW docs to reflect existence of CHECK constraints.

Generalize the remarks previously made about NOT NULL constraints to
CHECK constraints.

Etsuro Fujita

diff --git a/doc/src/sgml/fdwhandler.sgml b/doc/src/sgml/fdwhandler.sgml
index c1daa4be5a25412b2e04b8fc600b64b5b6a93e54..5af41318e5c17efe66e321af9514933b8d0686c0 100644 (file)
--- a/doc/src/sgml/fdwhandler.sgml
+++ b/doc/src/sgml/fdwhandler.sgml
@@ -242,13 +242,13 @@ IterateForeignScan (ForeignScanState *node);
 
     
      Note that PostgreSQL's executor doesn't care
-     whether the rows returned violate any NOT NULL
-     constraints that were defined on the foreign table columns — but
-     the planner does care, and may optimize queries incorrectly if
-     NULL values are present in a column declared not to contain
-     them.  If a NULL value is encountered when the user has
-     declared that none should be present, it may be appropriate to raise an
-     error (just as you would need to do in the case of a data type mismatch).
+     whether the rows returned violate any constraints that were defined on
+     the foreign table — but the planner does care, and may optimize
+     queries incorrectly if there are rows visible in the foreign table that
+     do not satisfy a declared constraint.  If a constraint is violated when
+     the user has declared that the constraint should hold true, it may be
+     appropriate to raise an error (just as you would need to do in the case
+     of a data type mismatch).