 ALTER TABLE cdm.src_mapped ADD KEY (question_ppi_code);
 CREATE INDEX mapped_p_id_and_ppi ON cdm.src_mapped (participant_id, question_ppi_code);
 CREATE INDEX mapped_qr_id_and_ppi ON cdm.src_mapped (questionnaire_response_id, question_ppi_code);
-*/
+
 -- -------------------------------------------------------------------
 -- source_file: src/location.sql
 -- -------------------------------------------------------------------

-- -------------------------------------------------------------------

-- Do not set locks, allow dirty reads.
/*
SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;

INSERT INTO cdm.src_clean

-- 'value_source_concept_id' and 'value_concept_id' - the same
-- relation.
-- -------------------------------------------------------------------

DROP TABLE IF EXISTS cdm.src_mapped;
CREATE TABLE cdm.src_mapped
(
