Re: Separate HEAP WAL replay logic into its own file

> On Jun 17, 2024, at 23:01, Melanie Plageman <melanieplageman@gmail.com> wrote:
> 
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> On Mon, Jun 17, 2024 at 2:20 AM Li, Yong <yoli@ebay.com> wrote:
>> 
>> Hi PostgreSQL hackers,
>> 
>> For most access methods in PostgreSQL, the implementation of the access method itself and the implementation of its WAL replay logic are organized in separate source files.  However, the HEAP access method is an exception.  Both the access method and the WAL replay logic are collocated in the same heapam.c.  To follow the pattern established by other access methods and to improve maintainability, I made the enclosed patch to separate HEAP’s replay logic into its own file.  The changes are straightforward.  Move the replay related functions into the new heapam_xlog.c file, push the common heap_execute_freeze_tuple() helper function into the heapam.h header, and adjust the build files.
> 
> I'm not against this change, but I am curious at what inspired this.
> Were you looking at Postgres code and simply noticed that there isn't
> a heapam_xlog.c (like there is a nbtxlog.c etc) and thought that you
> wanted to change that? Or is there some specific reason this would
> help you as a Postgres developer, user, or ecosystem member?
> 
> - Melanie

As a newcomer, when I was walking through the code looking for WAL replay related code, it was relatively easy for me to find them for the B-Tree access method because of the “xlog” hint in the file names. It took me a while to find the same for the heap access method. When I finally found them (via text search), it was a small surprise. Having different file organizations for different access methods gives me this urge to make everything consistent. I think it will make it easier for newcomers, and it will reduce the mental load for everyone to remember that heap replay is inside the heapam.c not some “???xlog.c”.

Yong