Re: [HACKERS] SSI memory mitigation & false positive degradation

2010-12-29 Thread Kevin Grittner
"Kevin Grittner" wrote: >> Any chance of upgrading the lock to a relation lock, or killing >> the serializable transaction instead? > > Absolutely. Good suggestion. Thanks! I pushed a TODO SSI comment at the appropriate point with my ideas on how best to fix this. I want to stick with the

Re: [HACKERS] SSI memory mitigation & false positive degradation

2010-12-29 Thread Kevin Grittner
Heikki Linnakangas wrote: > Looking at the predicate lock splitting, it occurs to me that > it's possible for a non-serializable transaction to be canceled if > it needs to split a predicate lock held by a concurrent > serializable transaction, and you run out of space in the shared > memory pre

Re: [HACKERS] SSI memory mitigation & false positive degradation

2010-12-29 Thread Heikki Linnakangas
On 26.12.2010 21:40, Kevin Grittner wrote: To recap, I've had an open question on the Serializable Wiki page[1] since January about how we should handle long-running transactions. The algorithm published by Cahill et al requires keeping some transaction information in memory for all committed tra

Re: [HACKERS] SSI memory mitigation & false positive degradation

2010-12-27 Thread Kevin Grittner
I wrote: > Dan and I have now implemented most of the mitigation techniques > ..., and I now feel confident I have a good grasp of how long each > type of data is useful. (By useful I mean that to maintain data > integrity without them it will be necessary to roll back some > transactions which