Upgrade code should be executed conditionally to avoid errors when upgrade is...

Upgrade code should be executed conditionally to avoid errors when upgrade is not applicable to given version and should be skipped.

hive/db/sql_scripts/upgrade/upgrade_runtime_migration.sql

@@ -2,6 +2,13 @@ SET ROLE hivemind;
 
 --- Put runtime data migration code here
 
+DO
+$$
+BEGIN
+
+IF EXISTS (SELECT column_name FROM information_schema.columns WHERE table_name='hivemind_app.hive_posts' and column_name='tags_ids') THEN
+  RAISE NOTICE 'Performing TAG-IDs migration';
+
 WITH data_source AS
 (
   SELECT p.id AS post_id, unnest(p.tags_ids) AS tag_id
@@ -24,6 +31,12 @@ TABLESPACE haf_tablespace
 ALTER TABLE hivemind_app.hive_post_tags INHERIT hive.hivemind_app;
 
 ANALYZE VERBOSE hivemind_app.hive_post_tags;
+ELSE
+  RAISE NOTICE 'TAG-IDs migration skipped';
+END IF;
+END
+$$
+;
 
 --- Must be at the end
 TRUNCATE TABLE hivemind_app.hive_db_data_migration;