数据库安装及数据库问题解决方法(五)

构建数据表t，其中构建专门的索引对象。





SQL> create table t as select * from dba_objects;

Table created

--索引对象1

SQL> create index idx_t_owner on t(owner);

Index created

--索引对象2

SQL> create index idx_t_id on t(object_id);

Index created



SQL> exec dbms_stats.gather_table_stats(user,'T',cascade => true);

PL/SQL procedure successfully completed

同时，我们准备四个SQL作为演示DEMO。





explain plan for select * from t where wner='SYS';

select * from table(dbms_xplan.display);

explain plan for select * from t where wner='SCOTT';

select * from table(dbms_xplan.display);

explain plan for select * from t where object_id between 10 and 50000;

select * from table(dbms_xplan.display);

explain plan for select * from t where object_id between 1 and 100;

select * from table(dbms_xplan.display);

CURSOR_SHARING=SIMILAR | EXACT | FORCE

db_file_multiblock_read_count

sort_area_size

db_keep_cache_size

log_buffer

db_block_buffers

----------------------------------------------------------------------------------------------------------------------------------

HWM 高水位

如何知道一个表的高水位

1、首先对表进行分析

execute dbms_stats.gather_table_stats()

ora-14401: inserted partition key is outside specified partition

插入的分区键值大于分区键

ORA-01008: not all variables bound

动态sql语句里:1这种变量出现了重复

-----------------双重调用变量------------------------

eval echo "$""$a"port

试试这个

我测试：

$ aport=1010

$ b=a

$ eval echo "$""$b"port

1010

-------------------------------------------------------------------------

alter index IDX_TB_INTERACTSRVLOG_1 rebuild



ORA-14086: a partitioned index may not be rebuilt as a whole

分区表需要一个一个分区rebuild