Sunday, October 12, 2014

Latest Oracle allows SELECT without SELECT...FOR UPDATE

Digging through a backlog of Oracle blogs, I came across an gem in a presentation from AMIS (on Slideshare). Got to bullet point 5 on slide 63 and boom !

You all know that when you grant SELECT on a table to a user, they can do a SELECT FOR UPDATE, locking records in the table and preventing other updates or deletes. [Some client tools may do that in the background. ]

Well finally Oracle have cottoned on to that too, and there's a lighter-weight "READ" privilege in which won't allow SELECT FOR UPDATE.

This will make DBAs very happy. Actually it won't. The natural state of a DBA is grumpy, at least when in the vicinity of a developer or salesman.

PS. Why would SELECT FOR UPDATE ever be a good idea for a user with no UPDATE privilege ?
If I had to guess, I'd say it went back to a 'pre-read consistency' model when you might use a SELECT FOR UPDATE to try to select data that wasn't being updated.