ALTERINDEX索引名 REBUILD ONLINE vsALTERINDEX索引名 REBUILD; alter index rebuild online实质上是扫描表而不是扫描现有的索引块来实现索引的重建. alter index rebuild 只扫描现有的索引块来实现索引的重建。 rebuild index online在执行期间不会阻塞DML操作,但在开始和结束阶段,需要请求模式为4的TM锁。因此,如果在r...
non-unique index generally Inlist iterator and union all. Nested loop joins Single table, Multi-column index (access/filter, and skip scan) Index-only query (range scan, full scan, fast full scan, index joins) Bitmap access (with multiple bitmaps per key value) Bitmap and / or / minu...
12. 在某个用户下找所有的索引 select user_indexes.table_name, user_indexes.index_name,uniqueness, column_name from user_ind_columns, user_indexes where user_ind_columns.index_name = user_indexes.index_name and user_ind_columns.table_name = user_indexes.table_name order by user_indexes.table...
Remote port : 123 Local address : 10.75.141.70 (0A4B8D46) Delay should be less than 30 Leap status : Normal seconds. Version Mode :4 : Server Stratum :3 Poll interval : 6 (64 seconds) Precision : -24 (0.000000060 seconds) Root delay : 0.065979 seconds Root dispersion : 0.111664 ...
Oracle五种索引: 1)btree index:几乎所有的关系型数据库中都有btree类型索引,也是被最多使用的。其树结构与二叉树比较类似,根据rid快速定位所访问的行。 B-Tree索引是基于二叉树的,由分支块(branch block)和叶块(leaf block)组成。在树结构中,位于最底层底块被称为叶块,包含每个被索引列的值和行所对应的rowid...
You cannot builda B-tree or bitmap index on a LOB column. 1.4.2 Indexing LOB Columns Using a Text Index Depending on the nature of the contents of the LOB column, one of the Oracle Text options couldalso be used for building indexes. For example, if a text document is stored in a...
Enhancements for Bitmap IndexesSeveral changes enhance query performance when bitmap indexes are used. One of these changes lifts a restriction whereby the use of the ALTER TABLE statement could invalidate a bitmap index. A new feature introduces two new ALTER TABLE statement options: ...
INDEX_NAME String 索引的名称。 INDEX_TYPE String 索引的类型(NORMAL、BITMAP、FUNCTION-BASED NORMAL、FUNCTION-BASED BITMAP 或 DOMAIN)。 TABLE_OWNER String 索引对象的所有者。 TABLE_NAME String 索引对象的名称。 TABLE_TYPE String 索引对象的类型(例如 TABLE、CLUSTER)。
INDEX_TYPE String Typ des Indexes (NORMAL, BITMAP, FUNCTION-BASED NORMAL, FUNCTION-BASED BITMAP oder DOMAIN). TABLE_OWNER String Besitzer des Objekts im Index. TABLE_NAME String Name des Objekts im Index. TABLE_TYPE String Typ des Objekts im Index (z. B. TABLE, CLUSTER). UNIQUENESS String...
SQL> create bitmap index bowie_kid_fk_i on bowie_kid(dad_id); Index created. SQL> create index bowie_kid_fk2_i on bowie_kid(dad_id) invisible; Index created. Oracle Database 12c allows us to now create multiple indexes on the same column list, providing only one index is visible...