On 28.12.09 18:54 , Kevin Grittner wrote:
> To give some idea of the scope of development, Michael Cahill added
> SSI to InnoDB by modifying 250 lines of code and adding 450 lines of
> code; however, InnoDB already had the S2PL option and the prototype
> implementation isn't as sophisticated as I feel is necessary for
> real production use (particularly regarding the granularity of SIREAD
> locks). I'm assuming it would take more to reach real production
> quality in PostgreSQL. My SWAG would be to multiply by two or
> three.
I believe the hard part of implementing true serializability is not the
actual SSI or S2PL algorithm, but rather the necessary predicate locking
strategy.
So I think checking how InnoDB tackles that and how much of it's code is
invovled might give a more realistic estimate of the effort required.
best regards,
Florian Plug
