-- AlterTable ALTER TABLE "website_event" ADD COLUMN "visit_id" UUID NULL; UPDATE "website_event" SET visit_id = uuid_in(overlay(overlay(md5(CONCAT(session_id::text, to_char(date_trunc('hour', created_at), 'YYYY-MM-DD HH24:00:00'))) placing '4' from 13) placing '8' from 17)::cstring) WHERE visit_id IS NULL; ALTER TABLE "website_event" ALTER COLUMN "visit_id" SET NOT NULL; -- CreateIndex CREATE INDEX "website_event_visit_id_idx" ON "website_event"("visit_id"); -- CreateIndex CREATE INDEX "website_event_website_id_visit_id_created_at_idx" ON "website_event"("website_id", "visit_id", "created_at");