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...
BIG_ZIGGY_LO_ORDERKEY_I BITMAP 843144 DISABLED BIG_ZIGGY_LO_ORDERKEY_I3 NORMAL 1921296 ADVANCED LOW We notice the B-Tree Index is indeed now smaller at just 1921296 leaf blocks, down from 2506552 leaf blocks, but still not as small as the 843144 leaf blocks of the Bitmap Index. However...
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...
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: ...
(1)If youdo not specify a tablespace for the LOB data, then the tablespace ofthe table is used for the LOB data and index. (2)If youspecify a tablespace for the LOB data, then both the LOB data and index use thetablespace that was specified. ...
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...
I’ll next create a standard bitmap index on the ALBUM_ID column and collect a few statistics: 1 2 3 4 5 6 7 8 SQL> create bitmap index big_dwh_table_album_id_i on big_dwh_table(album_id); Index created. SQL> exec dbms_stats.gather_table_stats(ownname=> 'BOWIE', tabname=...
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...