On Wed, Jan 11, 2017 at 10:42 PM, Craig Ringer <craig@2ndquadrant.com> wrote: > There is no code yet. Code review and testing is where things get firmer. > > My personal stance right now is that I'd like to see catalog-decared typed > variables. I would prefer them to be transactional and would at least oppose > anything that didn't allow future room for that capability. I'd prefer that > non-transactional vars be clearly declared as such. > > In the end though... I'm not the one implementing it. I can have some > influence through the code review process. But it's whoever steps up with a > proposed implementation that has the biggest say. The rest of us can say yes > or no to some degree... but nobody can make someone else implement something > they don't want.
There is not a agreement on the form of session variables.
Today I found on net a documentation to DB2 "CREATE VARIABLE" command. I had not any idea, so this statement exists already, although it is old feature - I found a doc from 2007.
The DB2 design is very similar to my proposal - secured access, persistent metadata, unshared untransactional data limmited by session.
They doesn't use a access functions - the access is with notation schemaname.variablename. I proposed this syntax as next step in implementation.
The DB2 authors doesn't propose transactional variables - when user needs XA behave, then global temporary tables should be used.
My patch was marked as "returned with feedback". Personally, I had not a idea what can be next step and what is preferred design, if some preferred design exists. I don't know what I have to change on my proposal.
I understand, so there are two different concepts - 1. using variables for adhoc writing like T-SQL, MySQL or 2. using variables as global session objects for stored procedures.
The @1 area is partially solved by psql session variables or by pgAdmin scripting functionality. @2 is partially solved by GUC but without possibility to set a access rights.
I didn't found any implementation of XA variables or persistent variables on the world.
