Re: [HACKERS] What I'm working on
От | Stupor Genius |
---|---|
Тема | Re: [HACKERS] What I'm working on |
Дата | |
Msg-id | 000201bdcf03$e850c1a0$e198accf@darren обсуждение исходный текст |
Список | pgsql-hackers |
> > I have been thinking about the blocksize patch, and I now think it is > > good we never installed it. I think we need to enable rows to span more > > than one block. That is what commercial databases do, and I think this > > is a much more general solution to the problem than increasing the block > > size. > > Hrmmm...what does one gain over the other though? The way I saw > it (sorry Darren, don't mean to oversimplify it), but making the blocksize > changeable was largely a matter of Darren making sure that all the > dependencies were covered through the code. What is making a row span > multiple blocks going to give us? Truly variable length "blocksizes"? Would theoretically remove the postgres maximum size limit on a tuple and make it limited by the OS file-size limit. Right now max-tuple-size and blocksize are the same, with the blocksize being changable only at compile-time. With the outdated patch that I have, this would change to run-time. Would be less important if chaining existed, but might be a decent stop-gap feature until then. I know that Oracle has chaining and they warn that it does have an effect on performance since a second (or more) tuple fetch has to be done. But it that's what someone needs for big tuples, that's the price then. I'll have more opinions after next week. Darren
В списке pgsql-hackers по дате отправления: