--* observation_lda_pin:
--*   attr:
--*     fillcolor: '1'
--*   desc: Filters OMOP observation table by kept sites.
--*   ext: sql
--*   inputs:
--*   - observation
--*   - keep_sites
--* 

SELECT observation.*
FROM observation
INNER JOIN keep_sites ON keep_sites.data_partner_id = observation.data_partner_id