Re: DropRelFileLocatorBuffers

At Fri, 08 Jul 2022 11:52:45 +0900 (JST), Kyotaro Horiguchi <horikyota.ntt@gmail.com> wrote in 
> > I wouldn't mind if we took "Locator" out of the name of that function
> > and just called it DropRelFileBuffers or DropRelationBuffers or
> > something. That would be shorter, and maybe more intuitive.
> 
> Thanks. Will propose that.

I thought for a moment that "Relation" sounded better but that naming
is confusing in bufmgr.c, where functions take Relation and those take
RelFileLocator exist together. So the (second) attached introduces
"RelFile" to represent RelFileNode excluding RelFileLocator.

The function CreateAndCopyRelationData exists since before b0a55e4329
but renamed since it takes RelFileLocators.

While working on this, I found that the following coment is wrong.

 *		FlushRelationsAllBuffers
 *
 *		This function flushes out of the buffer pool all the pages of all
 *		forks of the specified smgr relations.  It's equivalent to calling
 *		FlushRelationBuffers once per fork per relation.  The relations are
 *		assumed not to use local buffers.

It is equivalent to calling FlushRelationBuffers "per relation". This
is attached as the first patch, which could be thought as a separate
patch.

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center