2026-03-12 20:23:15

tpt/dba.sql

@@ -0,0 +1,97 @@
+-- Copyright 2018 Tanel Poder. All rights reserved. More info at http://tanelpoder.com
+-- Licensed under the Apache License, Version 2.0. See LICENSE.txt for terms & conditions.
+
+--------------------------------------------------------------------------------
+--
+-- File name:   dba.sql (version 0.2)
+-- Purpose:     Convert Data Block Address (a 6 byte hex number) to file#, block#
+--              and find to which segment it belongs
+--
+-- Author:      Tanel Poder
+-- Copyright:   (c) http://www.tanelpoder.com
+--              
+-- Usage:       @dba <data_block_address>
+--              @dba 40EB02
+-- 	        
+--	        
+-- Other:       This script also tries to identify the segment into which this
+--              block belongs. It first queries X$BH, as if this block is really
+--              hot, it should be in buffer cache. Note that you can change this
+--              query to use V$BH if you dont have access to X$ tables.
+--              If the block is not in buffer cache anymore, then this script
+--              can query DBA_EXTENTS next, but this can be a IO intensive operation
+--              on some systems, so if X$BH already answers your question, press
+--              CTRL+C here.
+--
+--------------------------------------------------------------------------------
+
+col rfile# new_value v_dba_rfile
+col block# new_value v_dba_block
+col bigfile_block# new_value v_bigfile_block
+col dba_object head object for a40 truncate
+col dba_DBA head DBA for a20
+
+
+select 
+	dbms_utility.data_block_address_file(to_number('&1','XXXXXXXXXX')) RFILE#, 
+	dbms_utility.data_block_address_block(to_number('&1','XXXXXXXXXX')) BLOCK#,
+  TO_NUMBER('&1','XXXXXXXXXX') bigfile_block#,
+  '-- alter system dump datafile '||dbms_utility.data_block_address_file(to_number('&1','XXXXXXXXXX'))
+  ||' block '||dbms_utility.data_block_address_block(to_number('&1','XXXXXXXXXX')) dump_cmd
+from dual;
+
+pause Press enter to find the segment using V$BH (this may take CPU time), CTRL+C to cancel: 
+
+select  /*+ ORDERED */
+        decode(bh.state,0,'free',1,'xcur',2,'scur',3,'cr',4,'read',5,'mrec',
+             6,'irec',7,'write',8,'pi', 9,'memory',10,'mwrite',
+             11,'donated', 12,'protected',13,'securefile', 14,'siop',15,'recckpt'
+        ) state,
+        decode(bh.class,1,'data block',2,'sort block',3,'save undo block', 
+               4,'segment header',5,'save undo header',6,'free list',7,'extent map', 
+               8,'1st level bmb',9,'2nd level bmb',10,'3rd level bmb', 11,'bitmap block',
+               12,'bitmap index block',13,'file header block',14,'unused', 
+               15,'system undo header',16,'system undo block', 17,'undo header',
+               18,'undo block'
+        ) block_class,
+	o.object_type,
+	o.owner||'.'||o.object_name		dba_object,
+	bh.tch,
+	bh.mode_held,
+    decode(bitand(bh.flag,1),0, 'N', 'Y')       dirty,
+    decode(bitand(bh.flag,16), 0, 'N', 'Y')     temp,
+    decode(bitand(bh.flag,1536), 0, 'N', 'Y')   ping,
+    decode(bitand(bh.flag,16384), 0, 'N', 'Y')  stale,
+    decode(bitand(bh.flag,65536), 0, 'N', 'Y')  direct, 
+  bh.cr_scn_bas,
+  bh.cr_scn_wrp,
+  cr_scn_wrp * power(2, 32) + cr_scn_bas full_scn,
+	trim(to_char(bh.flag, 'XXXXXXXX'))	||':'||
+	trim(to_char(bh.lru_flag, 'XXXXXXXX')) 	flg_lruflg,
+	bh.dirty_queue				DQ
+from
+	x$bh		bh,
+	dba_objects	o
+where
+	bh.obj = o.data_object_id
+and	(
+      (file#  = &v_dba_rfile and  dbablk = &v_dba_block)
+    or 
+      dbablk = &v_bigfile_block)
+order by
+	tch asc
+/
+
+pause Press enter to query what segment resides there using DBA_EXTENTS (this can be IO intensive), CTRL+C to cancel: 
+
+select owner, segment_name, partition_name, tablespace_name 
+from dba_extents
+where 
+    relative_fno = &v_dba_rfile
+and &v_dba_block between block_id and block_id + blocks - 1
+union all
+select owner, segment_name, partition_name, tablespace_name 
+from dba_extents
+where 
+    &v_bigfile_block between block_id and block_id + blocks - 1
+/