2026-05-01 14:48:00

divers/purge_all_AWR_snap.md

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+## Purge all AWR snapshots
+
+> To run from `CDB$ROOT` and not inside a **PDB**.
+
+```sql
+DECLARE
+  v_lo_snap_id NUMBER;
+  v_hi_snap_id NUMBER;
+  v_awr_dbid   NUMBER;
+BEGIN
+  -- 1. Get the DBID that actually exists in the AWR repository
+  SELECT DISTINCT dbid INTO v_awr_dbid FROM dba_hist_snapshot WHERE ROWNUM = 1;
+
+  -- 2. Find the min and max snapshot IDs for that specific DBID
+  SELECT min(snap_id), max(snap_id)
+    INTO v_lo_snap_id, v_hi_snap_id
+    FROM dba_hist_snapshot
+   WHERE dbid = v_awr_dbid;
+
+  IF v_lo_snap_id IS NOT NULL THEN
+    DBMS_OUTPUT.PUT_LINE('Deleting snapshots for DBID ' || v_awr_dbid || 
+                         ' from ' || v_lo_snap_id || ' to ' || v_hi_snap_id);
+    
+    DBMS_WORKLOAD_REPOSITORY.DROP_SNAPSHOT_RANGE(
+      low_snap_id  => v_lo_snap_id,
+      high_snap_id => v_hi_snap_id,
+      dbid         => v_awr_dbid
+    );
+    
+    DBMS_OUTPUT.PUT_LINE('AWR Snapshots cleared.');
+  ELSE
+    DBMS_OUTPUT.PUT_LINE('No snapshots found in dba_hist_snapshot.');
+  END IF;
+EXCEPTION
+  WHEN TOO_MANY_ROWS THEN
+    DBMS_OUTPUT.PUT_LINE('Error: Multiple DBIDs found in AWR. Please specify one manually.');
+  WHEN NO_DATA_FOUND THEN
+    DBMS_OUTPUT.PUT_LINE('Error: No snapshot data exists to delete.');
+END;
+/
+```
+
+Verify:
+```sql
+select min(snap_id),max(snap_id), dbid from dba_hist_snapshot group by dbid;
+```
+
+To take a snapshot:
+```sql
+execute dbms_workload_repository.CREATE_SNAPSHOT;
+```