CREATEINDEXindex_nameONtable_name(column1[,column2,...]);Code language:SQL (Structured Query Language)(sql) In this syntax: First, specify the name of the index. The index name should be meaningful and include table alias and column name(s) where possible, along with the suffix_Isuch as...
Oracle does not index table rows in which all key columns are null except in the case of bitmap indexes. Therefore, if you want an index on all rows of a table, then you must either specifyNOTNULLconstraints for the index key columns or create a bitmap index. Restrictions on Bitmap I...
CREATE INDEXTYPESyntax create_index::= Description of the illustration create_index.eps (cluster_index_clause::=, table_index_clause::=, bitmap_join_index_clause::=) cluster_index_clause::= Description of the illustration cluster_index_clause.eps (index_attributes::=) table...
MySQL 创建索引(Create Index)的方法和语法结构及例子 CREATE INDEX Syntax CREATE [UNIQUE|FULLTEXT|SPATIAL] INDEX index_name [index_type] ON tbl_name (index_col_name,...) [index_type] index_col_name: col_name [(length)] [ASC | DESC] index_type: USING {BTREE | HASH | RTREE} 复制代码...
CREATE TABLESyntax CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name [(create_definition,...)] [table_options] [select_statement] create_definition: col_name type [NOT NULL | NULL] [DEFAULT default_value] [AUTO_INCREMENT] [PRIMARY KEY] [reference_definition] or PRIMARY KEY (index_col_nam...
An example in the next section illustrates the syntax. Field definitions The following attributes can be set on a field when creating an index. Expand table AttributeDescription name Required. Sets the name of the field, which must be unique within the fields collection of the index or ...
http://download.oracle.com/docs/cd/E11882_01/server.112/e17118/statements_7002.htm#SQLRF01402 表空间(tableSpace) 段(segment) 盘区(extent) 块(block) 关系 一. Storage 参数说明 1. INITIAL Specify the size of the first extent of the object. Oracle allocates space for this ...
For string columns, indexes can be created that use only the leading part of column values, usingcol_name(length)syntax to specify an index prefix length: Prefixes can be specified forCHAR,VARCHAR,BINARY, andVARBINARYkey parts. Prefixesmustbe specified forBLOBandTEXTkey parts. Additionally,BLOBand...
managed system identity. Properties ofaccessCredentialsincludeapplicationId(Microsoft Entra ID application ID that was granted access permissions to your specified Azure Key Vault), andapplicationSecret(authentication key of the registered application). An example in the next section illustrates the syntax. ...
SQL Syntax SQL Syntax ABORT ALTER AUDIT POLICY ALTER COLUMN ENCRYPTION KEY ALTER COORDINATOR ALTER DATABASE ALTER DATABASE LINK ALTER DEFAULT PRIVILEGES ALTER DIRECTORY ALTER FOREIGN DATA WRAPPER ALTER FUNCTION ALTER GLOBAL CONFIGURATION ALTER GROUP ALTER INDEX ALTER LANGUAGE ALTER...