Instead of simply expanding the section on sub-queries, which may still be worthwhile, it seems that we have effectively introduced a new "kind" of query - namely one that mixes both query DDL and update DDL into a kind of hybrid query. An entire section describing the means to implement these queries and the limitations thereof would seem advisable as the current material is spread throughout the documentation.
Some areas to address would: Select queries that cause/utilize: function-based modifications CTE-based modifications FDW/dblink-based modifications I guess the main question is if someone were to put this together would it likely be included in the "queries" section of the documentation. Also, are there any other thoughts to add; and is something like this documented in a ToDo somewhere already? The proposed patch; while warranting a technical review (namely that the presence of functions in a sub-select can cause the sub-query to update the database), seems to add one more place to go find this information without adding a central index or summary that someone learning the system could directly comprehend/learn as opposed to it being some allowed/disallowed side-effect to something else. David J. -- View this message in context: http://postgresql.1045698.n5.nabble.com/Doc-Patch-Subquery-section-to-say-that-subqueries-can-t-modify-data-tp5766574p5766580.html Sent from the PostgreSQL - hackers mailing list archive at Nabble.com. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
