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

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