Re: [HACKERS] WAL logging problem in 9.4.3?

On Mon, May 20, 2019 at 03:54:30PM +0900, Kyotaro HORIGUCHI wrote:
> Following this direction, the attached PoC works *at least for*
> the wal_optimization TAP tests, but doing pending flush not in
> smgr but in relcache.

This task, syncing files created in the current transaction, is not the kind
of task normally assigned to a cache.  We already have a module, storage.c,
that maintains state about files created in the current transaction.  Why did
you use relcache instead of storage.c?

On Tue, May 21, 2019 at 09:29:48PM +0900, Kyotaro HORIGUCHI wrote:
> This is a tidier version of the patch.

> - Move the substantial work to table/index AMs.
> 
>   Each AM can decide whether to support WAL skip or not.
>   Currently heap and nbtree support it.

Why would an AM find it important to disable WAL skip?