[Q]
[A] analyze
Analyze table tablename compute statistics;
Analyze index indexname estimate statistics;
ANALYZE TABLE tablename COMPUTE STATISTICS
FOR TABLE
FOR ALL COLUMNS
FOR ALL INDEXES
FOR ALL INDEXED COLUMNS;
。
,
Dbms_utility(8i )
Dbms_stats(8i )
dbms_stats.gather_schema_stats(ownname=>User,estimate_percent=>100,cascade=> TRUE);
1. , DBMS_STATS, Analyze 。
a) , , Table
b) 。
c) Compute Statistics: , , ,
d)
e)
2. DBMS_STATS
a) Validate Structure
b) CHAINED ROWS, CLUSTER TABLE , Analyze 。
c) DBMS_STATS Analyze, Cascade False, True
3. oracle 9 External Table,Analyze , DBMS_STATS 。
[Q]
[A] rebuild ,
rebuild ,
alter index index_name rebuild tablespace ts_name
storage(……);
, , ,
SQL> set heading off
SQL> set feedback off
SQL> spool d:\index.sql
SQL> SELECT 'alter index ' || index_name || ' rebuild '
||'tablespace INDEXES storage(initial 256K next 256K pctincrease 0);'
FROM all_indexes
WHERE ( tablespace_name != 'INDEXES'
OR next_extent != ( 256 * 1024 )
)
AND owner = USER
SQL>spool off
alter index index_name coalesce, leaf block
, , 。