[RFC PATCH 01/23] vinyl: do not turn REPLACE into INSERT when processing DML request

[Vladimir Davydov]

On Tue, Jul 10, 2018 at 03:15:27PM +0300, Konstantin Osipov wrote:
> * Vladimir Davydov <vdavydov.dev at gmail.com> [18/07/08 22:52]:
> > Since in presence of secondary indexes we read the primary index when
> > processing a REPLACE request anyway, we turn it into INSERT if no tuple
> > matching the new tuple is found so that INSERT+DELETE gets annihilated
> > on compaction.
> > 
> > However, in the scope of #2129 we are planning to optimize the read out
> > so that this transformation won't be possible anymore. So let's remove
> > it now.
> 
> Ugh. What if we deal with a space which has a unique secondary
> key, so optimization B is not applicable. You removed optimization
> A for all spaces. 

The optimization works even if secondary indexes are unique.