On 10/26/17, Wout Mertens <wout.mert...@gmail.com> wrote:
> I have a table with an indexed json field, and I want to know the maximum
> value of that field.
>
>     create table events(id integer primary key, json JSON);
>     create index t on events(json_extract(json, '$.ts));
>
> If I do
>
>     select max(json_extract(json, '$.ts')) from events;
>
> it does a table scan with the index,
>
> Is this an optimization opportunity for calculated indexes?

It is.  There is a min/max optimization to deal with this situation,
but it currently does not know about indexes on expressions.

-- 
D. Richard Hipp
d...@sqlite.org
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