Re: Alternative MySQL PEAR DB sequence behavior

Oleg Rekutin wrote: > > Current MySQL sequence emulation simply keeps adding and adding IDs to the > sequence's table. This bothered me, because a lot of sequences with a lot of > IDs are just going to take up space for no reason. > > So I modified it to keep track of just one value... Haven't tested it > rigorously, but AFAIK it works. Patch is quoted below. (So here I am, having > wasted 1.5 hours on this patch when I have an urgent project otherwise :).) > > It also backwards-compatible, as it cleans up the garbage from the old-style > sequences (otherwise UPDATE fails), so that nothing has to be done on the > part of the user when the new mechanism is used. In addition, since the new- > style sequences use the same tables w/ an AUTO_INCREMENT id, it is also > backwards-compatible in the sense that if the user downgrades to the old- > style mechanism or moves the DB & application to a server with an older > version of PEAR DB, everything should still work (it will just keep on > inserting values). > > Deep inside I want all sequences to be contained in one table, but that's > too much of a pain in the ass to do, plus various concurrency issues arise > (there are concurrency issues nonetheless, mostly arising from the fact if > two clients attempt to create two sequences simultaneously... CREATE > DATABASE will fail for one of them... might want to use CREATE DATABASE IF > NOT EXISTS then?). > > Again, you might want to run tests of your own... Works for me :) I've committed this patch now, and it works fine except that the first id returned seems to be 2? At least in the case of DB/tests/mysql/005.phpt. Any ideas? - Stig