Re: [Proposal] Fully WAL logged CREATE DATABASE - No Checkpoints - Mailing list pgsql-hackers

From Andres Freund
Subject Re: [Proposal] Fully WAL logged CREATE DATABASE - No Checkpoints
Date
Msg-id 71BB0D91-0308-4134-BCDB-4D2567B27569@anarazel.de
Whole thread Raw
In response to Re: [Proposal] Fully WAL logged CREATE DATABASE - No Checkpoints  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: [Proposal] Fully WAL logged CREATE DATABASE - No Checkpoints
List pgsql-hackers
Hi,

On August 4, 2022 4:11:13 PM PDT, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>I wrote:
>> And while I'm piling on, how is this bit in RelationCopyStorageUsingBuffer
>> not completely broken?
>
>[pile^2]  Also, what is the rationale for locking the target buffer
>but not the source buffer?  That seems pretty hard to justify from
>here, even granting the assumption that we don't expect any other
>processes to be interested in these buffers (which I don't grant,
>because checkpointer).

I'm not arguing it's good or should stay that way, but it's probably okayish that checkpointer / bgwriter have access,
giventhat they will never modify buffers. They just take a lock to prevent concurrent modifications, which
RelationCopyStorageUsingBufferhopefully doesn't do.  

Andres
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.



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