摘要: Partition table 三种基本类型:ranage、hash、list partition table,另外composite partition就是对以上三种类型的组合类型.Composite PartitioningIdeal for both historical data and data placementProvides high availability and manageability,like range partitioningImproves performance for parallel DML and supports partition-wise joi 阅读全文
posted @ 2013-05-09 19:18 ArcerZhang 阅读(454) 评论(0) 推荐(0) 编辑
摘要: Hash Partitioning OverviewEasy to ImplementEnables better performance for PDML and partion-wise joinsPDML->P DML并发的修改数据partition-wise join只能的Join,只需要有用的Partition 进行Join,没用的partition就不参加JoinInserts rows into partitions automatically based on the hash of the partion keySupports(hash) local indexesp 阅读全文
posted @ 2013-05-09 16:56 ArcerZhang 阅读(201) 评论(0) 推荐(0) 编辑
摘要: Partitioning MethodsThe following partitioning methods are available:RangeHashListComposite按年度分区,2009年、2010年、...每年一张表;自oracle 9i以后,每个表空间可以指定不同的block_size,但是在分区表中,每个不同的分区必须使用相同的db_block_size;CREATE TABLE sales( acct_no NUMBER(5), person VARCHAR2(30), sales_amount... 阅读全文
posted @ 2013-05-09 16:46 ArcerZhang 阅读(262) 评论(0) 推荐(0) 编辑
摘要: Hash Clustered TablesHash Clustered Table的设计目的就是减少I/O的次数,如果设计不当(一般因为size大小设置问题) 导致overflow blocks ,无疑会增大I/O的次数,造成事倍功半.create hash clustered table and show it space info[oracle@arcerzhang usefull_scripts]$ lltotal 4-rw-r--r-- 1 oracle oinstall 3642 May 9 12:45 show_space.sql[oracle@arcerzhang useful. 阅读全文
posted @ 2013-05-09 13:34 ArcerZhang 阅读(236) 评论(0) 推荐(0) 编辑
摘要: Data Access MethodsTo enhance performance ,you can use the following data access methods:ClustersIndexesB-tree(nomal or reverse key)BitmapFunction basedIndex-organized tablesMaterialized viewsClustersCluster TypesHash Clustered TablesExample创建Index ClusterCREATE CLUSTER mycluster(deptno number(2)) s 阅读全文
posted @ 2013-05-09 11:47 ArcerZhang 阅读(177) 评论(0) 推荐(0) 编辑