Files
oracle/idev/dba_index_schema_fragmentation_report.sql
2026-03-12 21:23:47 +01:00

108 lines
4.6 KiB
SQL

-- +----------------------------------------------------------------------------+
-- | Jeffrey M. Hunter |
-- | jhunter@idevelopment.info |
-- | www.idevelopment.info |
-- |----------------------------------------------------------------------------|
-- | Copyright (c) 1998-2012 Jeffrey M. Hunter. All rights reserved. |
-- |----------------------------------------------------------------------------|
-- | DATABASE : Oracle |
-- | FILE : dba_index_schema_fragmentation_report.sql |
-- | CLASS : Database Administration |
-- | PURPOSE : Rebuilds an index to determine how fragmented it is. |
-- | NOTE : As with any code, ensure to test this script in a development |
-- | environment before attempting to run it in production. |
-- +----------------------------------------------------------------------------+
PROMPT
PROMPT +------------------------------------------------------------------------+
PROMPT | Index Fragmentation Report for a Specified Schema |
PROMPT |------------------------------------------------------------------------|
PROMPT | Rebuild the index when: |
PROMPT | [*] deleted entries represent 20% or more of the current entries |
PROMPT | [*] the index depth is more then 4 levels |
PROMPT | |
PROMPT | Possible candidate for bitmap index: |
PROMPT | [*] when distinctiveness is more than 99% |
PROMPT +------------------------------------------------------------------------+
PROMPT
ACCEPT schema CHAR prompt 'Schema name (% allowed) : '
PROMPT
SPOOL index_schema_fragmentation_report_&schema..lst
SET SERVEROUTPUT ON
SET ECHO OFF
SET FEEDBACK 6
SET HEADING ON
SET LINESIZE 180
SET PAGESIZE 50000
SET TERMOUT ON
SET TIMING OFF
SET TRIMOUT ON
SET TRIMSPOOL ON
SET VERIFY OFF
DECLARE
c_name INTEGER;
ignore INTEGER;
height index_stats.height%TYPE := 0;
lf_rows index_stats.lf_rows%TYPE := 0;
del_lf_rows index_stats.del_lf_rows%TYPE := 0;
distinct_keys index_stats.distinct_keys%TYPE := 0;
CURSOR c_indx IS
SELECT owner, table_name, index_name
FROM dba_indexes
WHERE owner LIKE upper('&schema')
AND owner NOT IN ('SYS','SYSTEM');
BEGIN
dbms_output.enable (1000000);
dbms_output.put_line ('Owner Index Name % Deleted Entries Blevel Distinctiveness');
dbms_output.put_line ('--------------- --------------------------------------- ----------------- ------ ---------------');
c_name := DBMS_SQL.OPEN_CURSOR;
FOR r_indx in c_indx LOOP
DBMS_SQL.PARSE(c_name,'analyze index ' || r_indx.owner || '.' || r_indx.index_name || ' validate structure', DBMS_SQL.NATIVE);
ignore := DBMS_SQL.EXECUTE(c_name);
SELECT
height
, DECODE (lf_rows, 0, 1, lf_rows)
, del_lf_rows
, DECODE (distinct_keys, 0, 1, distinct_keys)
INTO
height
, lf_rows
, del_lf_rows
, distinct_keys
FROM index_stats;
--
-- Index is considered as candidate for rebuild when :
-- - when deleted entries represent 20% or more of the current entries
-- - when the index depth is more then 4 levels.(height starts counting from 1 so > 5)
-- Index is (possible) candidate for a bitmap index when :
-- - distinctiveness is more than 99%
--
IF ( height > 5 ) OR ( (del_lf_rows/lf_rows) > 0.2 ) THEN
dbms_output.put_line ( RPAD(r_indx.owner, 16, ' ')
|| RPAD(r_indx.index_name, 40, ' ')
|| LPAD(ROUND((del_lf_rows/lf_rows)*100,3),17,' ')
|| LPAD(height-1,7,' ')
|| LPAD(ROUND((lf_rows-distinct_keys)*100/lf_rows,3),16,' '));
END IF;
END LOOP;
DBMS_SQL.CLOSE_CURSOR(c_name);
END;
/
SPOOL OFF
PROMPT Report written to index_schema_fragmentation_report_&schema..lst
PROMPT