SQL>EXPLAIN PLAN FOR SELECT * FROM SCOTT.EMP; --要解析的SQL脚本 查看执行计划: SELECT * FROM TABLE(DBMS_XPLAN.DISPLAY); 或者 select PLAN_TABLE_OUTPUT from table(dbms_xplan.display()); 缺点:没有输出运行时的相关统计信息(产生多少逻辑读,多少次递归调用,多少次物理读的情况),无法判断是处理了多少...
explain select... explain extended select... 将执行计划“反编译”成select语句 运行show warnings可以得到被mysql优化后的查询语句 explain partitions select...用于分区表 每列含义: 1.id 执行顺序 越大越早执行 2.select_type simple、primary、subquery..有没有包括子查询,查询复杂度 3.type ALL全表、inde...
be found on OTN on the Partitioning page 17 THE ORACLE OPTIMIZER EXPLAIN THE EXPLAIN PLAN Figure 21: Example plan output highlighting Partition pruning for a composite partitioned table When using composite partitioning, Oracle numbers each of the partitions from 1 to n (absolute partition numbers)...
Interval Partitioning-Robert Freemannotes that 11g "interval Partitioning makes it easier to manage partitions: "Wouldn't it be nice if you could just tell Oracle you wanted to partition every month and it would create the partitions for you? That is exactly what interval part...
select view_definition from V$FIXED_VIEW_DEFINITION WHERE view_name='V$PX_SESSION'; 60. dba_views 是从Oracle底层数据库的表中得到的,不是从X$表或者v$视图。 SQL> SET LONG 2000000 SQL>select text from dba_views where viewname='DBA_IND_PARTITIONS'; ...
I did wonder if the attempt to explain a plan that needed a non-existent partition had actually had the same effect of making Oracle create the partition, so I ran the query against user_tab_partitions again just to check that this hadn’t happend. So what’s going to happen at run-...
SQL>ALTERTABLEemp_partDROPPARTITIONS p4,p5UPDATEGLOBALINDEXES;SQL>ALTERTABLEemp_partTRUNCATEPARTITIONS p4,p5UPDATEGLOBALINDEXES; 1. 2. 如果你在不使用UPDATE GLOBAL INDEXES 语句的情况下删除或截断一个分区,你可以在USER_INDEXES或USER_IND_PARTITIONS 字典视图下查询ORPHANED_ENTRIES字段以找出是否有索引包含任何的...
Figure 2: Creating a text index in parallel Locally Partitioned Indexes It is possible to create a text index on a local partition basis – effectively each partition of the base table has its own index, and queries which span two or more partitions will access all the necessary local ...
ORA-10131: use v$sql_plan code path for explain plan ORA-10132: dump plan after compilation ORA-10133: testing for SQL Memory Management ORA-10134: tracing for SQL Memory Management for session ORA-10135: CBO do not count 0 rows partitions ORA-10136: CBO turn off fix for bug 1089848 ...
SQL> select partition_name,high_value,num_rows,blocks from dba_tab_partitions where table_name='MACLEAN'; PARTITION_NAME HIGH_VALUE NUM_ROWS BLOCKS --- --- --- --- P1 99999 38789142 533240 P3 100001 0 0 P4 MAXVALUE 0 0 SQL> alter table maclean split...