完全统计法:analyze table table_name compute statistics; 抽样估计法:analyze table table_name estimate statistics sample 30 percent; 对表使用抽样估计法要比完全统计法的生成统计速度要快,但是统计数据可能不够精确。在开发过程中,我们可能要涉及很多的表的查询,而我们在使用CBO的时候就需要经常对这些表执行分析统...
TRUNCATE TABLE 表名;ANALYZE TABLE 表名 ESTIMATE STATISTICS;
完全统计法:analyze table table_name compute statistics; 抽样估计法:analyze table table_name estimate statistics sample 30 percent; 其中,完全统计可以针对表的不同内容进行统计,如: analyze table t1 compute statistics for table; analyze table t2 compute statistics for all columns; analyze table t3 comput...
SQL> exec dbms_stats.gather_schema_stats(ownname=>'scott',options=>'gather auto',estimate_percent=>dbms_stats.auto_sample_size,degree=>6); 具体的参数可以根据实际情况修改，也可以加其他的参数进来 全库的话，10g会自动分析的，但是也可以收到分析，统计分析要消耗大量资源，建议不要在业...
ANALYZE TABLE table_name ESTIMATE STATISTICS; ANALYZE TABLE table_name COMPUTE STATISTICS FOR TABLE FOR ALL INDEXES FOR ALL INDEXED COLUMNS; execute dbms_stats.gather_table_stats(ownname => 'OWNER', tabname => 'TABLE_NAME' , estimate_percent => null ,method_opt => 'for all indexed columns...
SQL>create table t1 as select * from dba_objects; SQL>create index idx_t1 on t1(object_id); (1)analyze索引统计信息: SQL>analyze index idx_t1 delete statistics; (2)对表收集统计信息,并且以估算模式,采样比为15%: SQL>analyze table t1 estimate statistics sample 15 percent for table; ...
Analyze脚本内容如下: sqlplus scott/tiger << EOF set pagesize 5000 set heading off SPOOL ANALYTAB.SQL SELECT "ANALYZE TABLE SCOTT."||TABLE_NAME||" ESTIMATE STATISTICS SAMPLE 20 PERCENT ;" FROM USER_TABLES; SPOOL OFF SPOOL ANALYIND.SQL ...
ANALYZETABLEAESTIMATE/COMPUTESTATISTICS; ESTIMATE估计数据有可能会错误,但速度快,COMPUTE准确但速度慢。 2、查询行数量和blocks SELECTblocks,empty_blocks,num_rowsFROMuser_tablesWHEREtable_name='A'; 2、允许表行移动 altertableAenablerowmovement; 3、空间收缩 ...
ANALYZE INDEX indexname COMPUTE STATISTICS;:收集索引的统计信息。 ANALYZE TABLE tablename ESTIMATE STATISTICS SAMPLE x PERCENT;:通过抽样来估计统计信息,适用于大表。 ANALYZE TABLE tablename DELETE STATISTICS;:删除表的统计信息。 使用DBMS_STATS包: DBMS_STATS.GATHER_TABLE_STATS(ownname, tabname);:收集...
If you want tovalidate a partitioned table, then you must have the INSERT objectprivilege on the table into which you list analyzed rowids, or you must havethe INSERT ANY TABLE system privilege. 三. Syntax 详细语法如下: ANALYZE TABLE tablenameCOMPUTE|ESTIMATE|DELETE STATISTICS ptnOption options...