2026-03-12 20:23:15

idev/perf_db_block_buffer_usage.sql

@@ -0,0 +1,40 @@
+-- +----------------------------------------------------------------------------+
+-- |                          Jeffrey M. Hunter                                 |
+-- |                      jhunter@idevelopment.info                             |
+-- |                         www.idevelopment.info                              |
+-- |----------------------------------------------------------------------------|
+-- |      Copyright (c) 1998-2011 Jeffrey M. Hunter. All rights reserved.       |
+-- |----------------------------------------------------------------------------|
+-- | DATABASE : Oracle                                                          |
+-- | FILE     : perf_db_block_buffer_usage.sql                                  |
+-- | CLASS    : Tuning                                                          |
+-- | PURPOSE  : Report on the state of all DB_BLOCK_BUFFERS. This script must   |
+-- |            be run as the SYS user.                                         |
+-- | NOTE     : As with any code, ensure to test this script in a development   |
+-- |            environment before attempting to run it in production.          |
+-- +----------------------------------------------------------------------------+
+
+SET LINESIZE 135
+SET PAGESIZE 9999
+SET VERIFY   off
+
+COLUMN block_status      HEADING "Block Status"
+COLUMN count             HEADING "Count"
+
+SELECT
+    DECODE(state, 0, 'Free',
+                  1, DECODE(lrba_seq, 0, 'Available', 'Being Modified'),
+                  2, 'Not Modified',
+                  3, 'Being Read',
+                     'Other') block_status
+  , count(*) count
+FROM
+  sys.x$bh
+GROUP BY
+    DECODE(state, 0, 'Free',
+                  1, DECODE(lrba_seq, 0, 'Available', 'Being Modified'),
+                  2, 'Not Modified',
+                  3, 'Being Read',
+                     'Other')
+/
+