Analizando y estableciendo los índices que deben ser recreados

REM
REM rebuild_indx.sql
REM
REM Copyright (c) Oracle Software, 1998 - 2000
REM
REM Author : Jurgen Schelfhout
REM MODIFICIACION: Ronald Vargas Quesada 2006-2009
REM
REM This script will analyze all the indexes for a given schema
REM or for a subset of schema's. After this the dynamic view
REM index_stats is consulted to see if an index is a good
REM candidate for a rebuild or for a bitmap index.
REM
REM Database Version : 9iR1, 9iR2,10g
REM
REM =============================================================
prompt
ACCEPT spoolfile CHAR prompt 'Output-file : ';
ACCEPT schema CHAR prompt 'Schema name (% allowed) : ';
prompt
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 Possible candidate for bitmap index :
prompt - when distinctiveness is more than 99%
prompt
set linesize 1000
set serveroutput 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');
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;
/
set verify on