Add missing schema migration file

Author: erikd

schema/migration-2-0026-20230208.sql

@@ -0,0 +1,19 @@
+-- Persistent generated migration.
+
+CREATE FUNCTION migrate() RETURNS void AS $$
+DECLARE
+  next_version int ;
+BEGIN
+  SELECT stage_two + 1 INTO next_version FROM schema_version ;
+  IF next_version = 26 THEN
+    EXECUTE 'ALTER TABLE "reverse_index" ALTER COLUMN "min_ids" SET NOT NULL' ;
+    -- Hand written SQL statements can be added here.
+    UPDATE schema_version SET stage_two = next_version ;
+    RAISE NOTICE 'DB has been migrated to stage_two version %', next_version ;
+  END IF ;
+END ;
+$$ LANGUAGE plpgsql ;
+
+SELECT migrate() ;
+
+DROP FUNCTION migrate() ;