Re: bzr commit into mysql-6.0-codebase-bugfixing branch (roy.lyseng:3836) WL#5347

[Øystein Grøvlen]

Roy Lyseng wrote:
> I mean that both strategies are applicable only when there are no 
> correlated outer tables, ie all outer tables are non-correlated. 

I do not think this is correct.  According to the patterns in the 
description you have added, the patterns of MaterializeLookup is a 
subset of the patterns for MaterializeScan.

> If 
> there are correlated tables in the suffix, MaterializeScan must be used. 
> If there are correlated tables only in the prefix, then 
> MaterializeLookup must be used. 

I think MaterializeScan can handle correlated tables in the prefix, but 
the heuristic is to ues MaterializeLookup in this case.

--
Øystein