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explain plan from @?/rdbms/admin/utlxpls select /*+ index(tablename,index_name) */ * from table_name; 

pstack

select /* + push_subq */  * from emp a,dept bwhere a.deptno=b.deptno and exists (select 1 from dept1 where dept1.danme=b.dname);

alter table t shring space;alter table t enable row movementalter index index_name coalescealter index index_name rebuild tablesapce cr_dataalter index index_name validate structure

select /*+use_concat */ * from goodsbase  access()filter()

参数cursor_sharing:提示：强制SQL硬解析，避免children cursor过多还来的负面性能影响cursor_sharing_exact 例sqlplus  "/as sysdba"create user dbusrgfc101 identified by hhgfc;grant connect...

bitmap conversion from /to rowidsalter session set "_b_tree_bitmap_plans"=false;alter session set "_b_tree_bitmap_plans"=true; 

select sql_id,hash_value,dbms_utility.sqlid_to_sqlhash(sql_id)from v$sql where rownum<9 select    lower(trim('&1')) sql_id  , trunc(mod(sum((instr('0123456789abcdfghjkmnpqr...

当某个索引处于monitoring usage的时候，如果使用dbms_stats去分析表并且同时分析索引，会将该索引的v$object_usage.USED设置为TRUE，导致监控了N天的可疑索引前功近弃。这并不是我们所希望的. 如果使用analyze，索...

CLUSTER can’t be renamed.FUNCTION can’t be renamed.INDEX ALTER INDEX old_name RENAME TO new_name;INDEX PARTITION ALTER INDEX index_name RENAME PARTITION partition TO new_name;INDEX SUB PARTITION ALT...

for large transactionsselect sum(used_ublk) from v$transaction;select * from v$fast_start_transactionsselect * from v$fast_start_servers;for large queriesselect count(*) from v$sesssion_longops w...

9i-10g 术语1、用“library cache lock”代表名为library cache lock的enqueue；2、用“library cache pin”代表名为library cache pin的enqueue；3、用“Child library cache”代表名为library cache的子latch...

一、先决条件1。表空间需求system表空间至少10M空间可用2。系统参数show parameter shared_pool_sizeshow prameter java_pool_sizealter system set shared_pool_size='200M' scope=spfile;alter system set ...

一.系统当前状态[root@node1 ora11g]#  cat /proc/meminfo | grep -i hugepages HugePages_Total:     0 HugePages_Free:      0 HugePages_Rsvd: &nb...