Hi čt 3. 9. 2020 v 15:43 odesílatel Konstantin Knizhnik < k.knizh...@postgrespro.ru> napsal:
> Hi hackers, > > Recently I have asked once again by one of our customers about login > trigger in postgres. People are migrating to Postgres from Oracle and > looking for Postgres analog of this Oracle feature. > This topic is not new: > > > https://www.postgresql.org/message-id/flat/1570308356720-0.post%40n3.nabble.com#4748bcb0c5fc98cec0a735dbdffb0c68 > > https://www.postgresql.org/message-id/flat/OSAPR01MB507373499CCCEA00EAE79875FE2D0%40OSAPR01MB5073.jpnprd01.prod.outlook.com#ed50c248be32be6955c385ca67d6cdc1 > > end even session connect/disconnect hooks were sometimes committed (but > then reverted). > As far as I understand most of the concerns were related with disconnect > hook. > Performing some action on session disconnect is actually much more > complicated than on login. > But customers are not needed it, unlike actions performed at session start. > > I wonder if we are really going to make some steps in this directions? > The discussion above was finished with "We haven't rejected the concept > altogether, AFAICT" > > I have tried to resurrect this patch and implement on-connect trigger on > top of it. > The syntax is almost the same as proposed by Takayuki: > > CREATE EVENT TRIGGER mytrigger > AFTER CONNECTION ON mydatabase > EXECUTE {PROCEDURE | FUNCTION} myproc(); > > I have replaced CONNECT with CONNECTION because last keyword is already > recognized by Postgres and > make ON clause mandatory to avoid shift-reduce conflicts. > > Actually specifying database name is redundant, because we can define > on-connect trigger only for self database (just because triggers and > functions are local to the database). > It may be considered as argument against handling session start using > trigger. But it seems to be the most natural mechanism for users. > > On connect trigger can be dropped almost in the same way as normal (on > relation) trigger, but with specifying name of the database instead of > relation name: > > DROP TRIGGER mytrigger ON mydatabase; > > It is possible to define arbitrary number of on-connect triggers with > different names. > > I attached my prototype implementation of this feature. > I just to be sure first that this feature will be interested to community. > If so, I will continue work in it and prepare new version of the patch > for the commitfest. > > I have a customer that requires this feature too. Now it uses a solution based on dll session autoloading. Native solution can be great. +1 Pavel Example > > -- > Konstantin Knizhnik > Postgres Professional: http://www.postgrespro.com > The Russian Postgres Company > >
