14-unique-hash-indexes.sql

-- HACK: This migration is commented out, because it's turned out to be
-- trouble. But, removing it from the sequence entirely also causes trouble.
-- So, this is a no-op.

--
-- The unique constraint got left out of an earlier actioncounters migration,
-- so this schematic migration forcibly cleans up the few duplicates and adds
-- the unique constraint.
--
-- There should only be about 50 duplicates in 180000 or so production records.
--
-- CREATE TEMPORARY TABLE dup_actioncounter_hashes
--     SELECT unique_hash
--     FROM actioncounters_actioncounterunique
--     GROUP BY unique_hash 
--     HAVING count(unique_hash) > 1;
-- 
-- DELETE FROM actioncounters_actioncounterunique 
--     WHERE unique_hash IN
--         (SELECT unique_hash FROM dup_actioncounter_hashes);
-- 
-- DROP INDEX actioncounters_actioncounterunique_unique
--     ON actioncounters_actioncounterunique;
-- 
-- ALTER TABLE actioncounters_actioncounterunique 
--     ADD UNIQUE actioncounters_actioncounterunique_unique (unique_hash);