Re: [PATCH] 2PC state files on shared memory - Mailing list pgsql-hackers

From Michael Paquier
Subject Re: [PATCH] 2PC state files on shared memory
Date
Msg-id c64c5f8b0908091936n78b8d0ch9bfa029e0c9a15af@mail.gmail.com
Whole thread Raw
In response to Re: [PATCH] 2PC state files on shared memory  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: [PATCH] 2PC state files on shared memory  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
After making a lot of tests, state file size is not more than 600B.
In some cases, it reached a maximum of size of 712B and I used such transactions in my tests.
 
> I think setting the size parameter for this would be a frightfully
> difficult problem; the fact that average installations wouldn't use it
> doesn't make that any better for those who would.  After our bad
> experiences with fixed-size FSM, I'm pretty wary of introducing new
> fixed-size structures that the user is expected to figure out how to
> size.
The patch has been designed such as if a state file has a size higher than what has been decided by the user,
it will be written to disk instead of shared memory. So it will not represent a danger for teh stability of the system.
The case of too many prepared transactions is also covered thanks to max_prepared_transactions.
 
Regards,

--
Michael Paquier

NTT OSSC

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