diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/fdwhandler.sgml | 7 | ||||
| -rw-r--r-- | doc/src/sgml/rules.sgml | 8 |
2 files changed, 9 insertions, 6 deletions
diff --git a/doc/src/sgml/fdwhandler.sgml b/doc/src/sgml/fdwhandler.sgml index cfa68084179..67f512d1240 100644 --- a/doc/src/sgml/fdwhandler.sgml +++ b/doc/src/sgml/fdwhandler.sgml @@ -429,11 +429,14 @@ AddForeignUpdateTargets (Query *parsetree, <literal>wholerow</literal>, or <literal>wholerow<replaceable>N</></literal>, as the core system can generate junk columns of these names. + If the extra expressions are more complex than simple Vars, they + must be run through <function>eval_const_expressions</function> + before adding them to the targetlist. </para> <para> - This function is called in the rewriter, not the planner, so the - information available is a bit different from that available to the + Although this function is called during planning, the + information provided is a bit different from that available to other planning routines. <literal>parsetree</> is the parse tree for the <command>UPDATE</> or <command>DELETE</> command, while <literal>target_rte</> and diff --git a/doc/src/sgml/rules.sgml b/doc/src/sgml/rules.sgml index bcbc1703355..6344da95855 100644 --- a/doc/src/sgml/rules.sgml +++ b/doc/src/sgml/rules.sgml @@ -167,12 +167,12 @@ <para> <command>DELETE</command> commands don't need a normal target list - because they don't produce any result. Instead, the rule system + because they don't produce any result. Instead, the planner adds a special <acronym>CTID</> entry to the empty target list, to allow the executor to find the row to be deleted. (<acronym>CTID</> is added when the result relation is an ordinary - table. If it is a view, a whole-row variable is added instead, - as described in <xref linkend="rules-views-update">.) + table. If it is a view, a whole-row variable is added instead, by + the rule system, as described in <xref linkend="rules-views-update">.) </para> <para> @@ -194,7 +194,7 @@ column = expression</literal> part of the command. The planner will handle missing columns by inserting expressions that copy the values from the old row into the new one. Just as for <command>DELETE</>, - the rule system adds a <acronym>CTID</> or whole-row variable so that + a <acronym>CTID</> or whole-row variable is added so that the executor can identify the old row to be updated. </para> |