1) I wasn't aware of an API to retrieve a schema. We could definitely
use that to avoid the need for views.
2) I agree, seems like a bug.
Mit freundlichen Grüßen,
------------------------------------------------------------------------
*Christian Beikov*
Am 17.05.2018 um 13:51 schrieb Michael Mior:
1) I'm not too familiar with ES so I didn't realize you could define
mappings. I don't see any obvious reason why we couldn't use those assuming
they're exposed via the ES API.
2) I was not aware of this and not sure whether it was intentional. It
seems like a bug to me though.
3) Whenever you want to see how to build a particular query, you may find
it helpful to run "EXPLAIN PLAN FOR <query>" in sqlline.
--
Michael Mior
[email protected]
Le jeu. 17 mai 2018 à 01:26, Andrei Sereda <[email protected]> a écrit :
Hello Calcite Devs,
I have some questions about ES adapter and custom predicates / projections
in Calcite. Your help is much appreciated.
1) All ES examples use a view (ZIPS
<
https://github.com/apache/calcite/blob/master/elasticsearch5/src/test/resources/elasticsearch-zips-model.json
)
which does explicit type cast, name alias and dictionary access (via _MAP)
for each field. If such view is not defined beforehand, making ad-hoc
queries becomes tedious. Is there a way to make it more user-friendly (eg.
using existing ES mapping) ?
Example: select cast(_MAP['city'] AS varchar(20)) AS \"city\" from ...
Why some adapters require explicit definition (eg. Mongo / ES) while others
don't (eg. Geode)
2) When not using explicit casting (or field alias) query literals are
converted to lower case:
SQL: select * from "elastic" where _MAP['Foo'] = 'BAR' (note upper-case)
ES Query: { "term": { "foo" : "bar" }} (note lower-case)
This is less intuitive. Is there a way to switch it off (customize) ?
3) How to build the following query using Algebra Builder (RelBuilder)
select * from "elastic" where _MAP['Foo'] = 'Bar'
I presume one has to use SqlItemOperator but I couldn't get it to work. Is
this related to (1) and (2) ?
Regards,
Andrei.
