Create index indexname on tablename(columnname[columnname...]) (2)反向索引。 Create index indexname on tablename(columnname[columnname...]) reverse (3)降序索引。 Create index indexname on tablename(columnname DESC[columnname...]) (4)位图索引。 Create BITMAP index indexname on tablename(...
SELECT /*+INDEX_FFS(BSEMPMS IN_EMPNAM)*/ * FROM BSEMPMS WHERE DPT_NO='TEC305'; 14. /*+ADD_EQUAL TABLE INDEX_NAM1,INDEX_NAM2,...*/ 提示明确进行执行规划的选择,将几个单列索引的扫描合起来. 例如: SELECT /*+INDEX_FFS(BSEMPMS IN_DPTNO,IN_EMPNO,IN_SEX)*/ * FROM BSEMPMS WHERE ...
Create index indexname on tablename(columnname[columnname...]) (2)反向索引。 Create index indexname on tablename(columnname[columnname...]) reverse (3)降序索引。 Create index indexname on tablename(columnname DESC[columnname...]) (4)位图索引。 Create BITMAP index indexname on tablename(...
OracleIndex索引介绍(SQL)假设我们要找索引中值为80的行从索引树的最上层入口开始定位到大于等于50然后往左找找到第2个分支块定位为75100最后再定位到叶块上找到80所对应的rowid然后根据rowid去读取数据块获取数据 OracleIndex索引介绍(SQL) 概述 索引在各种关系型数据库系统中都是举足轻重的组成部分,其对于提高检索...
ANALYZE INDEX statement, 7-200 ANALYZE TABLE statement, 7-200 ANCILLARY TO clause of CREATE OPERATOR, 7-341 AND operator, 3-11, 3-12 AND_EQUAL hint, 2-65 ANSI, B - 1 datatypes, 2-28 conversion to Oracle datatypes, 2-28 standards, xv, 1-2 supported datatypes, 2-12...
最適化プロセス全体の一環として、Oracleオプティマイザは主要問合せを最適化する前に、各インライン・ビュー(副問合せ)の再帰的最適化を実行します。このようなパターンは問合せの解析時間に影響し、効率性の低い実行計画が生成される可能性があります。次のようなより効率的なパターン・...
Unit Test PL/SQL Objects Related Technologies About Data Modeler in Oracle SQL Developer Use Data Miner in Oracle SQL Developer Support for Oracle TimesTen In-Memory Database Enter OLAP DML Statements in the Worksheet Support for Oracle REST Data Services...
oracle索引的操作 ORACLE对索引有两种访问模式. 索引唯一扫描 ( INDEX UNIQUE SCAN) 大多数情况下, 优化器通过WHERE子句访问INDEX. 例如: 表LODGING有两个索引 : 建立在LODGING列上的唯一性索引LODGING_PK和建立在MANAGER列上的非唯一性索引LODGING$MANAGER....
Oracle SQL Developer is a free, integrated development environment that simplifies the development and management of Oracle Database in both traditional and Cloud deployments. SQL Developer offers complete end-to-end development of your PL/SQL applications, a worksheet for running queries and scripts,...
Index represents an index on a table in Oracle NoSQL Database. It is an immutable object created from system metadata. Index is used to examine index metadata and used as a factory for IndexKey objects used for IndexKey operations in TableAPI. Indexes are created and managed using the ...