Re: heap_sync seems rather oblivious to partitioned tables(wal_level=minimal)

On 2018-09-19 12:06:47 +0900, Michael Paquier wrote:
> On Wed, Sep 19, 2018 at 01:14:10PM +1200, David Rowley wrote:
> > Wouldn't it be better to modify copy.c to just perform the heap_sync
> > on just the partitions it touches?
> 
> Yeah, my gut is telling me that this would be the best approach for now,
> still I am not sure that this is the best move in the long term.

ISTM heap_sync() would be the entirely wrong layer to handle
partitioning. For several reasons: 1) With pluggable storage, we want to
have multiple different table implementations, doing the syncing on the
heap_* for partitions would thus be wrong. 2) In just about all cases we
only want to sync a few partitions, there's not really a use-case for
doing syncs across all partitions imo.

> All the other callers of heap_sync don't care about partitioned
> tables, so we could add an assertion on RELKIND_PARTITIONED_TABLE.

Or rather, it should assert the expected relkinds?

Greetings,

Andres Freund