One more parameter used in the CREATE INDEX statement is COMPUTE STATISTICS. It is an optional parameter telling Oracle to collect the statistics during index creation. Further, this stats data would serve when choosing the “plan of execution” of SQL statements. However, since Oracle 10, the ...
(By default, Oracle Database creates B-tree indexes.) Bitmap indexes, which store rowids associated with a key value as a bitmap. Partitioned indexes, which consist of partitions containing an entry for each value that appears in the indexed column(s) of the table. Function-based index...
During index creation, as a leaf block becomes full, the database automatically compresses the block to the optimal level. When reorganizing an index block as a result of DML, if the database can create sufficient space for the incoming index entry, then a block split does not occur. Durin...
RC:Index Creation On 12.1.0.2 With Subpartitioning Much Bigger Than In 11g Last updated on NOVEMBER 07, 2023 Applies to: Oracle Database - Enterprise Edition - Version 12.1.0.2 and later Oracle Database Cloud Schema Service - Version N/A and later Oracle Database Exadata Cloud Machine - Ver...
Oracle Database - Enterprise Edition - Version 11.2.0.4 and later: ORA-1427 Attaching to Job Stopped During the Index Creation in Order to Restart It
online indexbuild (online create或者rebuild index)是Oracle的一个极其常用的online操作,我们知道当创建索引或者重建索引没有加online关键字的话,会请求表对象上的4号TM锁,而DML请求的是3号TM锁,3和4的TM锁并不兼容,所以在索引创建或者重建期间是无法进行DML操作的,等待事件为enq: TM – contention。
online index build(online create或者rebuild index)是Oracle的一个非常常用的online操作,我们知道当创建索引或者重建索引没有加online关键字的话,会请求表对象上的4号TM锁,而DML请求的是3号TM锁,3和4的TM锁并不兼容,所以在索引创建或者重建期间是无法进行DML操作的,等待事件为enq: TM – contention。
--Oracle 自动创建了索引并关联到约束, 索引名和约束名是相同的。 --验证下索引 SYS@anqing2(rac2)> selectindex_name,index_type,uniqueness,generated from user_indexes wheretable_name='UT'; INDEX_NAME INDEX_TYPE UNIQUENES GENERATED --- --- --- UC_PHONE NORMAL UNIQUE N --我们并没有创建索引,...
One notable aspect of the REBUILD operation is that the index will temporarily consume twice as much space during the rebuilding process due to the creation of the new index structure.The primary advantage of using the REBUILD statement is that it can effectively defragment an index and reclaim ...
online index build(online create或者rebuild index)是Oracle的一个非常常用的online操作,我们知道当创建索引或者重建索引没有加online关键字的话,会请求表对象上的4号TM锁,而DML请求的是3号TM锁,3和4的TM锁并不兼容,所以在索引创建或者重建期间是无法进行DML操作的,等待事...