Robert Haas escribió: > On Wed, Dec 16, 2009 at 10:29 AM, Andres Freund <and...@anarazel.de> wrote: > > On Wednesday 16 December 2009 16:24:42 Robert Haas wrote: > >> > Inserts and deletes follow the same protocol, obtaining an exclusive > >> > lock on the row after the one being inserted or deleted. The result > >> > of this locking protocol is that a range scan prevents concurrent > >> > inserts or delete within the range of the scan, and vice versa. > >> > > >> > That sounds like it should actually work. > >> > >> Only if you can guarantee that the database will access the rows using > >> some particular index. If it gets to the data some other way it might > >> accidentally circumvent the lock. That's kind of a killer in terms of > >> making this work for PostgreSQL. > > Isnt the whole topic only relevant for writing access? There you have to > > access the index anyway. > > Yeah, I guess you have to insert the new tuple. I guess while you > were at it you might check whether the next tuple is locked...
So you'd have to disable HOT updates when true serializability was active? -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
