On Wed, Apr 18, 2018 at 7:46 AM, Andres Freund <and...@anarazel.de> wrote: > On 2018-04-18 10:46:51 +0900, Michael Paquier wrote: >> On Tue, Apr 17, 2018 at 06:13:31PM -0700, Andres Freund wrote: >> > Not sure what you mean? >> >> Do you need help on it? I suggest that I could undertake the proposed >> patch and submit it earlier in the development cycle of v12. > > I think it's at the very least two months of serious development work to > get it into a state ready for submission. And a good chunk of that not > even sketched out. Replacing the hashtable is the easy part, the memory > management (Complicated due to lock-freeness. I'm thinking of using a > variant of epoch based reclamation) isn't really there, the management > of shared "open relations" state are the hard parts... > > So yes, I could use help on it, but it'll be a lot of actual design and > investigatory work. >
I think it makes sense to pursue that approach, but it might be worth considering some alternative till we have it. I remember last time (in 2015) we have discussed some another solution [1] to this problem (or similar) and we have left it unattended in the hope that we will get a better solution, but we are still in the same situation. I think in general it is better to go with the approach which can fix the root cause of the problem, but if that is going to take a long time, it is not terrible to provide some workable solution which can help users. [1] - https://www.postgresql.org/message-id/CAA4eK1JPLGjpMeJ5YLNE7bpNBhP2EQe_rDR%2BAw3atNfj9WkAGg%40mail.gmail.com -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com
