Re: Looking for help on query optimization statistics
To inject statistics, you need to implement your own RelMetadataProvider
and register it into your runtime environment.
I'm not able to find a valid example in Calcite, but there is a good
example you can find in Drill
On Mon, Nov 5, 2018 at 11:54 AM Tian Ye <yet@xxxxxxxxxx> wrote:
> I'm working on comparing the query plan generated by Calcite with that
> from a DBMS I'm developing.
> In particular, I can generate some TPC-H data and a SQL query, and I want
> to let Calcite generate as good query plan as it can. So far, I haven't
> passed any statistics to Calcite, so the query plan it generates is just a
> Now I wonder how I could pass statistics to Calcite. What I don't
> understand is that since Calcite does not load the data until query plan is
> actually executed, how could I pass statistics to it?
> I fail to find any document talking about how to do that in detail. The
> last paragraphs of http://calcite.apache.org/docs/adapter.html do
> mention it but are not so clear.
> Would you please help me?
> Thanks a lot.
> Tian Ye