On Tue, May 5, 2015 at 5:53 PM, Andres Freund <and...@anarazel.de> wrote:
> > > Was there any consideration for initializing restart_lsn to the latest > > WAL write pointer when a slot is created? Or for allowing an optional > > parameter in pg_create_(physical|logical)_replication_slot() for > > specifying the restart_lsn at slot creation? > > I've been wondering about allowing for the latter alternative. I could > have used it a couple times. The former doesn't make much sense to me, > it could be too far *ahead* in many cases actually. A patch for this > would be fairly trivial. > Attached is the patch that takes the former approach (initialize restart_lsn when the slot is created). I think it's better than the latter approach (depend on user to specify an LSN) because the LSN user specifies may have already been recycled. pg_create_logical_replication_slot() prevents LSN from being recycled that by looping (worst case 2 times) until there's no conflict with the checkpointer recycling the segment. So I have used the same approach. The function pg_create_physical_replication_slot() now has an additional boolean parameter 'activate' which user can use to allocate restart_lsn as part of the creation process. Best regards, -- Gurjeet Singh http://gurjeet.singh.im/
physical_repl_slot_activate_restart_lsn.patch
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