From f9f2fda79658cc8f898c6fa7ba6da9a1f394cdee Mon Sep 17 00:00:00 2001 From: Etsuro Fujita Date: Wed, 18 Sep 2019 18:50:00 +0900 Subject: [PATCH] Doc: Update FDW documentation about direct foreign table modification. 1. Commit 7086be6e3 should have documented the limitation that the direct modification is disabled when WCO constraints are present, but didn't, which is definitely my fault. Update the documentation (Postgres 9.6 onwards). 2. Commit fc22b6623 should have documented the limitation that the direct modification is disabled when generated columns are defined, but didn't. Update the documentation (Postgres 12 onwards). Author: Etsuro Fujita Discussion: https://postgr.es/m/CAPmGK14AYCPunLb6TRz1CQsW5Le01Z2ox8LSOKH0P-cOVDcQRA%40mail.gmail.com --- doc/src/sgml/fdwhandler.sgml | 8 +++++--- doc/src/sgml/postgres-fdw.sgml | 6 +++--- 2 files changed, 8 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/fdwhandler.sgml b/doc/src/sgml/fdwhandler.sgml index b54670b9f2..6587678af2 100644 --- a/doc/src/sgml/fdwhandler.sgml +++ b/doc/src/sgml/fdwhandler.sgml @@ -820,9 +820,11 @@ IsForeignRelUpdatable(Relation rel); row-by-row approach is necessary, but it can be inefficient. If it is possible for the foreign server to determine which rows should be modified without actually retrieving them, and if there are no local - triggers which would affect the operation, then it is possible to - arrange things so that the entire operation is performed on the remote - server. The interfaces described below make this possible. + structures which would affect the operation (row-level local triggers, + stored generated columns, or WITH CHECK OPTION + constraints from parent views), then it is possible to arrange things + so that the entire operation is performed on the remote server. The + interfaces described below make this possible. diff --git a/doc/src/sgml/postgres-fdw.sgml b/doc/src/sgml/postgres-fdw.sgml index e9ce39af64..634a7141ef 100644 --- a/doc/src/sgml/postgres-fdw.sgml +++ b/doc/src/sgml/postgres-fdw.sgml @@ -504,9 +504,9 @@ sending the whole query to the remote server if there are no query WHERE clauses that cannot be sent to the remote server, no local joins for the query, no row-level local BEFORE or - AFTER triggers on the target table, and no - CHECK OPTION constraints from parent views. - In UPDATE, + AFTER triggers or stored generated columns on the target + table, and no CHECK OPTION constraints from parent + views. In UPDATE, expressions to assign to target columns must use only built-in data types, IMMUTABLE operators, or IMMUTABLE functions, to reduce the risk of misexecution of the query. -- 2.40.0