From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 2 Aug 2018 12:43:56 +0300 From: Vladimir Davydov Subject: Re: [tarantool-patches] Re: [PATCH 24/25] Introduce _vinyl_deferred_delete system space Message-ID: <20180802094356.foz3jqbjqe347q2b@esperanza> References: <920a0685fd01546464585090dadf57732fa7a696.1532689066.git.vdavydov.dev@gmail.com> <20180731205427.GQ15235@chai> <20180801140018.ti22auajqiwlfyjn@esperanza> <20180801202501.GD15337@chai> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180801202501.GD15337@chai> To: Konstantin Osipov Cc: tarantool-patches@freelists.org List-ID: On Wed, Aug 01, 2018 at 11:25:01PM +0300, Konstantin Osipov wrote: > * Vladimir Davydov [18/08/01 18:14]: > > On Tue, Jul 31, 2018 at 11:54:27PM +0300, Konstantin Osipov wrote: > > > * Vladimir Davydov [18/07/27 16:55]: > > > > The space is a blackhole. It will be used for writing deferred DELETE > > > > statements generated by vinyl compaction tasks to WAL so that we can > > > > recover deferred DELETEs that hadn't been dumped to disk before the > > > > server was restarted. > > > > > > Why do you actually need a proto space for it? Please feel free to > > > put blackhole engine first in the list of engines. > > > > You mean making this space purely virtual? No record in _space, no info > > in snap file, just struct space in the cache? > > No, I mean no changes in sc_* methods, only a record in _space? But we need to install on_replace trigger on that space. OTOH we can do that in vinyl_engine_bootstrap or vinyl_engine_begin_initial_recovery - obviously the space isn't used during recovery from memtx snapshot, we only need the trigger on final recovery. Looks reasonable. Is this what you mean?