feat: enterprise audit fixes (schema resolution, race conditions, documentation)

postgresql/procedures/04_undo_partitioning.sql

@@ -0,0 +1,79 @@
+-- ============================================================================
+-- Reverts Zabbix partitioned tables back to standard non-partitioned tables.
+-- Existing partitioned tables will be renamed to *_part (data is preserved).
+-- ============================================================================
+
+DO $$
+DECLARE
+    v_row record;
+    v_table text;
+    v_part_table text;
+    v_schema text;
+BEGIN
+    FOR v_row IN SELECT * FROM partitions.config LOOP
+        v_table := v_row.table_name;
+        v_part_table := v_table || '_part';
+        
+        -- Determine schema of the partitioned table
+        SELECT n.nspname INTO v_schema
+        FROM pg_class c
+        JOIN pg_namespace n ON n.oid = c.relnamespace
+        WHERE c.relname = v_table AND c.relkind = 'p' AND pg_table_is_visible(c.oid);
+
+        IF v_schema IS NOT NULL THEN
+            RAISE NOTICE 'Reverting partitioned table %...', v_table;
+            
+            -- 1. Rename existing partitioned table to *_part
+            EXECUTE format('ALTER TABLE %I.%I RENAME TO %I', v_schema, v_table, v_part_table);
+            
+            -- 2. Create standard (unpartitioned) replacement table based on the structure
+            IF v_table = 'auditlog' THEN
+                -- For auditlog, we need to try and restore the original single-column PK (auditid) if possible
+                EXECUTE format('CREATE TABLE %I.%I (LIKE %I.%I INCLUDING DEFAULTS INCLUDING COMMENTS)', v_schema, v_table, v_schema, v_part_table);
+                BEGIN
+                    EXECUTE format('ALTER TABLE %I.%I ADD PRIMARY KEY (auditid)', v_schema, v_table);
+                EXCEPTION WHEN others THEN
+                    RAISE WARNING 'Failed to create primary key on auditlog, might already exist or duplicates present.';
+                END;
+                EXECUTE format('CREATE INDEX IF NOT EXISTS auditlog_1 ON %I.%I (userid, clock)', v_schema, v_table);
+                EXECUTE format('CREATE INDEX IF NOT EXISTS auditlog_2 ON %I.%I (clock)', v_schema, v_table);
+                EXECUTE format('CREATE INDEX IF NOT EXISTS auditlog_3 ON %I.%I (resourcetype, resourceid)', v_schema, v_table);
+                EXECUTE format('CREATE INDEX IF NOT EXISTS auditlog_4 ON %I.%I (recordsetid)', v_schema, v_table);
+                EXECUTE format('CREATE INDEX IF NOT EXISTS auditlog_5 ON %I.%I (ip)', v_schema, v_table);
+            ELSE
+                -- For others, copy everything including indexes
+                EXECUTE format('CREATE TABLE %I.%I (LIKE %I.%I INCLUDING ALL)', v_schema, v_table, v_schema, v_part_table);
+            END IF;
+            
+            RAISE NOTICE 'SUCCESS: % reverted to default. Partitioned data stored in % (You can DROP TABLE % CASCADE; later).', v_table, v_part_table, v_part_table;
+            
+        ELSIF EXISTS (SELECT 1 FROM pg_class WHERE relname = v_table AND relkind = 'r' AND pg_table_is_visible(oid)) THEN
+            RAISE NOTICE 'Table % is already a regular table. Skipping.', v_table;
+        ELSE
+            RAISE WARNING 'Partitioned table % not found!', v_table;
+        END IF;
+    END LOOP;
+    
+    -- Drop the housekeeper intercept trigger (dynamically determine schema for custom schema support)
+    SELECT n.nspname INTO v_schema
+    FROM pg_class c
+    JOIN pg_namespace n ON n.oid = c.relnamespace
+    WHERE c.relname = 'housekeeper' AND pg_table_is_visible(c.oid);
+
+    IF v_schema IS NOT NULL THEN
+        EXECUTE format('DROP TRIGGER IF EXISTS housekeeper_filter ON %I.housekeeper', v_schema);
+        RAISE NOTICE 'Housekeeper intercept trigger removed from %.housekeeper', v_schema;
+    ELSE
+        RAISE WARNING 'housekeeper table not found — trigger removal skipped.';
+    END IF;
+    
+    RAISE NOTICE '================================================================================';
+    RAISE NOTICE 'Undo complete. Partitioned tables have been renamed to *_part.';
+    RAISE NOTICE 'If you want to migrate your history back, you must do it manually:';
+    RAISE NOTICE '    INSERT INTO history SELECT * FROM history_part;';
+    RAISE NOTICE 'Once done, or if you do not need the data, drop the partitioned tables:';
+    RAISE NOTICE '    DROP TABLE history_part CASCADE;';
+    RAISE NOTICE 'After that, you can safely remove the partitions infrastructure:';
+    RAISE NOTICE '    DROP SCHEMA partitions CASCADE;';
+    RAISE NOTICE '================================================================================';
+END $$;