From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 1 Aug 2018 17:00:18 +0300 From: Vladimir Davydov Subject: Re: [PATCH 24/25] Introduce _vinyl_deferred_delete system space Message-ID: <20180801140018.ti22auajqiwlfyjn@esperanza> References: <920a0685fd01546464585090dadf57732fa7a696.1532689066.git.vdavydov.dev@gmail.com> <20180731205427.GQ15235@chai> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180731205427.GQ15235@chai> To: Konstantin Osipov Cc: tarantool-patches@freelists.org List-ID: 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? Hmm, I guess we can do that. However, I think that it's kinda weird to have a space that can be written to, but which doesn't exist in the data dictionary. This may also result in some anomalies, like the user can grant access to it although it doesn't actually exist in _space (yeah, this is pointless, I know, but still). Is there any reason to do that? Or do you mean something different by 'proto space'?