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From Sergi Vladykin <sergi.vlady...@gmail.com>
Subject Re: SQL Hash indexes
Date Sat, 19 Sep 2015 11:04:40 GMT
Not necessary, you can configure to have either sorted index or hash index
or both.
In the last case as far as I understand optimizer just will pick up hash
index for
equality conditions because it will have lower cost.

The only thing I'm currently not sure of is how to add this to configuration
(our indexed types config already looks like piece of crap, don't want to
complicate it even more).

Sergi

2015-09-18 19:05 GMT+03:00 Dmitriy Setrakyan <dsetrakyan@apache.org>:

> Sergi,
>
> Does it mean that field "a" will now have 2 indexes, hash and sorted?
>
> D.
>
> On Fri, Sep 18, 2015 at 4:01 PM, Sergi Vladykin <sergi.vladykin@gmail.com>
> wrote:
>
> > Guys,
> >
> > It seems that for simple equality queries like
> >
> > SELECT * FROM x WHERE a = ?
> >
> > it is more effective to use hash indexes which do not even need to be
> > snapshotable.
> > I think it will be easy to implement one based on ConcurrentHashMap.
> >
> > Thoughts?
> >
> > Sergi
> >
>

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