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)...
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...
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...
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-...
By definition of good range or list partitioning, fast index scans of the correct index partitions can result in very fast query times. Reverse Key Indexes These are designed to eliminate index hot spots on insert applications. These indexes are excellent for insert performance, but they are ...
Methods inherited from class java.lang.Object clone, finalize, getClass, notify, notifyAll, wait, wait, wait Methods inherited from interface com.tangosol.util.Filter and, asLimitFilter, associatedWith, forKeys, forPartitions, or, xor Field Detail EVAL_COST public static int EVAL_COST The e...
Default is none to not export the partitions by reference. Value none mean no translation and export of partition by reference like before. Value 'duplicate' will duplicate the referenced column in the partitioned table and apply the same partitioning from the referenced table to the partitioned ...
Oracle won’t bother to access partitions that won’t contain any data to satisfy the query. If all the data in a partition satisfies a part of the WHERE clause for the query, Oracle simply selects all the rows for the partition without bothering to evaluate the clause for each row. Par...
select * from v$reserved_words order by keyword asc; //order 后边不是必须的,那只是个排序,使结果不至于杂乱无章,如果用的是PL/SQL的话的SQL window的话,在获得结果后,可以点击按钮,使得查询结果不分页,然后可以 右击结果区空白处--->Export results--->Html file(推荐这个,其他格式也行),这样就不用每...
If you have multiple partitioned table, when exported to PostgreSQL some partitions could have the same name but different parent tables. This is not allowed, table name must be unique, in this case enable this directive. A partition will be renamed following the rule: "tablename"_part"pos"...