fix: automatic column additions, permissions grants and docs updates for seamless upgrades

postgresql/procedures/00_schema_create.sql

@@ -15,6 +15,14 @@ CREATE TABLE IF NOT EXISTS partitions.config (
     PRIMARY KEY (table_name)
 );
 
+-- Ensure the future_partitions column exists for users upgrading from older versions
+DO $$
+BEGIN
+    IF NOT EXISTS (SELECT 1 FROM information_schema.columns WHERE table_schema = 'partitions' AND table_name = 'config' AND column_name = 'future_partitions') THEN
+        ALTER TABLE partitions.config ADD COLUMN future_partitions integer NOT NULL DEFAULT 5;
+    END IF;
+END $$;
+
 -- Table to track installed version of the partitioning solution
 CREATE TABLE IF NOT EXISTS partitions.version (
     version text PRIMARY KEY,

postgresql/procedures/02_enable_partitioning.sql

@@ -74,11 +74,24 @@ BEGIN
 END $$;
 
 -- ==========================================================================
--- IMPORTANT: If the Zabbix Server connects with a non-superuser (e.g., 'zabbix'),
+-- IMPORTANT: To ensure the Zabbix Server can insert into the housekeeper
--- that user MUST have access to the partitions schema for the housekeeper trigger
+-- table without permission issues, we automatically grant access to the 
--- to work. Without these GRANTs, every INSERT into housekeeper will FAIL.
+-- partitions schema to the owner of the housekeeper table.
--- Uncomment and adjust the username below:
 -- ==========================================================================
--- GRANT USAGE ON SCHEMA partitions TO zabbix;
+DO $$
--- GRANT SELECT ON partitions.config TO zabbix;
+DECLARE
+    v_owner text;
+BEGIN
+    SELECT pg_get_userbyid(c.relowner) INTO v_owner
+    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_owner IS NOT NULL THEN
+        EXECUTE format('GRANT USAGE ON SCHEMA partitions TO %I', v_owner);
+        EXECUTE format('GRANT SELECT ON partitions.config TO %I', v_owner);
+        RAISE NOTICE 'Granted partitions schema permissions to housekeeper owner: %', v_owner;
+    ELSE
+        RAISE WARNING 'housekeeper table not found, could not grant permissions automatically!';
+    END IF;
+END $$;

postgresql/procedures/03_monitoring_view.sql

@@ -31,3 +31,12 @@ LEFT JOIN pg_inherits ON pg_inherits.inhparent = parent.oid
 LEFT JOIN pg_class child ON pg_inherits.inhrelid = child.oid
 WHERE parent.relkind = 'p' -- Only partitioned tables
 GROUP BY parent.relname, c.table_name, c.period, c.keep_history, c.future_partitions, c.last_updated;
+
+-- ============================================================================
+-- IMPORTANT: Since DROP VIEW / CREATE VIEW resets permissions, we automatically
+-- grant read access to PUBLIC. This ensures that whatever monitoring user
+-- (e.g. zbx_monitor) is connecting to the DB will always be able to read 
+-- the monitoring stats without manual intervention after upgrades.
+-- ==========================================================================
+GRANT USAGE ON SCHEMA partitions TO PUBLIC;
+GRANT SELECT ON partitions.monitoring TO PUBLIC;

postgresql/procedures/MANUAL.md

@@ -53,32 +53,34 @@ Once inside `psql`, connect to your Zabbix database (usually named `zabbix`):
 
 ## Step 3: Execute Installation Scripts
 
-Run the scripts in the following exact order. You can use the `\i` command in `psql` if you are in the `procedures` directory, or specify the full path.
+Run the scripts in the following exact order. You can execute them directly from your bash terminal, from within the interactive `psql` console, or by pasting their contents into a GUI tool (like pgAdmin).
 
-**1. Create the partitioning schema and config tables:**
 > [!NOTE]
-> **Zabbix 8.0+ Users:** Zabbix 8.0 introduced a new `history_json` table. Before running the script below, open `00_schema_create.sql` in a text editor and uncomment the lines specifically marked for Zabbix 8.0 at the end of the history tables block.
+> **Zabbix 8.0+ Users:** Zabbix 8.0 introduced a new `history_json` table. Before running the first script, open `00_schema_create.sql` in a text editor and uncomment the lines specifically marked for Zabbix 8.0 at the end of the history tables block.
 
+### Option A: From bash terminal (Recommended)
+If you are in your normal Linux terminal, run these commands one by one:
+```bash
+psql -U postgres -d zabbix -f 00_schema_create.sql
+psql -U postgres -d zabbix -f 01_maintenance.sql
+# MIGRATION STEP: The next script renames your existing large tables to `_old` 
+# and instantly creates new partitioned tables. This might take a few moments.
+psql -U postgres -d zabbix -f 02_enable_partitioning.sql
+psql -U postgres -d zabbix -f 03_monitoring_view.sql
+```
+
+### Option B: Inside interactive `psql`
+If you already connected via `psql` (as in Step 2), use the `\i` command:
 ```sql
 \i 00_schema_create.sql
-```
-
-**2. Install the maintenance logic and functions:**
-```sql
 \i 01_maintenance.sql
-```
-
-**3. Enable Partitioning (MIGRATION STEP):**
-*This step renames your existing large tables to `_old` and instantly creates new partitioned tables. This might take a few moments.*
-```sql
 \i 02_enable_partitioning.sql
-```
-
-**4. Create the Monitoring View:**
-```sql
 \i 03_monitoring_view.sql
 ```
 
+### Option C: GUI Tools (pgAdmin, DBeaver, etc.)
+If you use a visual database manager, simply open each file in your query editor and execute them one by one in the exact order (00, 01, 02, 03).
+
 ---
 
 ## Step 4: Schedule Automated Maintenance
@@ -127,6 +129,7 @@ SELECT
 FROM partitions.monitoring;
 EOF
 ```
+*(Note: If your Zabbix Agent is configured to look for custom queries in a different directory like `/etc/zabbix/postgresql/sql/`, modify the destination path above).*
 
 2. Configure the PostgreSQL Plugin by editing `/etc/zabbix/zabbix_agent2.d/plugins.d/postgresql.conf`. Ensure you have defined a session (e.g., `MY_DB`) and enabled custom queries:
 
@@ -159,3 +162,20 @@ sudo systemctl restart zabbix-agent2
 8. Click **Update**.
 
 **Congratulations!** Your Zabbix database is now fully partitioned, optimized, and monitored.
+
+---
+
+## Step 8: Upgrades & Updates
+
+To apply future updates or fixes to the partitioning logic, the scripts are fully idempotent and safe to re-run on a live database.
+Simply connect to `psql` and re-execute the updated scripts in order:
+
+```bash
+psql -U postgres -d zabbix -f 00_schema_create.sql
+psql -U postgres -d zabbix -f 01_maintenance.sql
+psql -U postgres -d zabbix -f 02_enable_partitioning.sql
+psql -U postgres -d zabbix -f 03_monitoring_view.sql
+```
+
+> [!WARNING]
+> If you update the agent SQL query, always remember to restart the agent (`sudo systemctl restart zabbix-agent2`) so it flushes its cache!

postgresql/procedures/README.md

@@ -231,8 +231,8 @@ GRANT USAGE ON SCHEMA partitions TO zbxpart_monitor;
 GRANT SELECT ON partitions.monitoring TO zbxpart_monitor;
 ```
 
-> [!WARNING]
+> [!NOTE]
-> Because `03_monitoring_view.sql` uses a `DROP VIEW` command to apply updates, re-running the script will destroy all previously assigned `GRANT` permissions. If you ever update the view script, you **must** manually re-run the `GRANT SELECT` command above to restore access for the `zbxpart_monitor` user!
+> The `03_monitoring_view.sql` script is designed to automatically execute `GRANT SELECT ON partitions.monitoring TO PUBLIC;` so that read access is never lost during upgrades when the view is recreated.
 
 ## Implementation Details
 

postgresql/template/zbx_pg_partitions_monitor_agent2.yaml

@@ -57,7 +57,7 @@ zabbix_export:
               preprocessing:
                 - type: JSONPATH
                   parameters:
-                    - '$.[?(@.table_name == "{#TABLE_NAME}")].future_partitions.first()'
+                    - '$.[?(@.table_name == "{#TABLE_NAME}")].actual_future_partitions.first()'
               master_item:
                 key: 'pgsql.custom.query["{$PG.CONNSTRING.AGENT2}",,,"{$PG.DBNAME}","partitions.get_all"]'
               tags: