2026-03-12 20:23:15

idev/dba_index_fragmentation.sql

@@ -0,0 +1,62 @@
+-- +----------------------------------------------------------------------------+
+-- |                          Jeffrey M. Hunter                                 |
+-- |                      jhunter@idevelopment.info                             |
+-- |                         www.idevelopment.info                              |
+-- |----------------------------------------------------------------------------|
+-- |      Copyright (c) 1998-2012 Jeffrey M. Hunter. All rights reserved.       |
+-- |----------------------------------------------------------------------------|
+-- | DATABASE : Oracle                                                          |
+-- | FILE     : dba_index_fragmentation.sql                                     |
+-- | CLASS    : Database Administration                                         |
+-- | PURPOSE  : To ascertain index fragmentation. As a rule of thumb if 10-15%  |
+-- |            of the table data changes, then you should consider rebuilding  |
+-- |            the index.                                                      |
+-- | NOTE     : As with any code, ensure to test this script in a development   |
+-- |            environment before attempting to run it in production.          |
+-- +----------------------------------------------------------------------------+
+
+SET ECHO        OFF
+SET FEEDBACK    OFF
+SET HEADING     ON
+SET LINESIZE    180
+SET PAGESIZE    50000
+SET TERMOUT     ON
+SET TIMING      OFF
+SET TRIMOUT     ON
+SET TRIMSPOOL   ON
+SET VERIFY      OFF
+
+CLEAR COLUMNS
+CLEAR BREAKS
+CLEAR COMPUTES
+
+PROMPT 
+PROMPT +------------------------------------------------------------------------+
+PROMPT | Calculate Index Fragmentation for a Specified Index                    |
+PROMPT +------------------------------------------------------------------------+
+
+PROMPT 
+ACCEPT index_name CHAR prompt 'Enter index name [SCHEMA].index_name : '
+
+ANALYZE INDEX &index_name VALIDATE STRUCTURE;
+ 
+COLUMN name           HEADING 'Index Name'          FORMAT a30
+COLUMN del_lf_rows    HEADING 'Deleted|Leaf Rows'   FORMAT 999,999,999,999,999
+COLUMN lf_rows_used   HEADING 'Used|Leaf Rows'      FORMAT 999,999,999,999,999
+COLUMN ibadness       HEADING '% Deleted|Leaf Rows' FORMAT 999.99999
+ 
+SELECT
+    name
+  , del_lf_rows
+  , lf_rows - del_lf_rows lf_rows_used
+  , TO_CHAR( del_lf_rows /(DECODE(lf_rows,0,0.01,lf_rows))*100,'999.99999') ibadness
+FROM   index_stats
+/
+ 
+PROMPT 
+PROMPT Consider rebuilding any index if % of Deleted Leaf Rows is > 20%
+PROMPT 
+
+UNDEFINE index_name
+
+SET FEEDBACK    6