Thomas Munro 212fab9926 Relax transactional restrictions on ALTER TYPE ... ADD VALUE (redux). ... Originally committed as 15bc038f (plus some follow-ups), this was reverted in 28e07270 due to a problem discovered in parallel workers. This new version corrects that problem by sending the list of uncommitted enum values to parallel workers. Here follows the original commit message describing the change: To prevent possibly breaking indexes on enum columns, we must keep uncommitted enum values from getting stored in tables, unless we can be sure that any such column is new in the current transaction. Formerly, we enforced this by disallowing ALTER TYPE ... ADD VALUE from being executed at all in a transaction block, unless the target enum type had been created in the current transaction. This patch removes that restriction, and instead insists that an uncommitted enum value can't be referenced unless it belongs to an enum type created in the same transaction as the value. Per discussion, this should be a bit less onerous. It does require each function that could possibly return a new enum value to SQL operations to check this restriction, but there aren't so many of those that this seems unmaintainable. Author: Andrew Dunstan and Tom Lane, with parallel query fix by Thomas Munro Reviewed-by: Tom Lane Discussion: https://postgr.es/m/CAEepm%3D0Ei7g6PaNTbcmAh9tCRahQrk%3Dr5ZWLD-jr7hXweYX3yg%40mail.gmail.com Discussion: https://postgr.es/m/4075.1459088427%40sss.pgh.pa.us		2018-10-09 12:51:01 +13:00
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src	Relax transactional restrictions on ALTER TYPE ... ADD VALUE (redux).	2018-10-09 12:51:01 +13:00
bug.template	Stamp HEAD as 12devel	2018-06-30 12:47:59 -04:00
KNOWN_BUGS	Remove extra newlines at end and beginning of files, add missing newlines	2010-08-19 05:57:36 +00:00
Makefile	Remove maintainer-check target, fold into normal build	2013-10-10 20:11:56 -04:00
MISSING_FEATURES	Remove extra newlines at end and beginning of files, add missing newlines	2010-08-19 05:57:36 +00:00
TODO	Change documentation references to PG website to use https: not http:	2017-05-20 21:50:47 -04:00