42 | CREATING INDEX in Oracle SQL | Oracle PL/SQL Programming
CREATE INDEX
Purpose
Use the CREATE INDEX statement to create an index on:
One or more columns of a table, a partitioned table, an index-organized table, or a cluster
One or more scalar typed object attributes of a table or a cluster
A nested table storage table for indexing a nested table column
An index is a schema object that contains an entry for each value that appears in the indexed column(s) of the table or cluster and provides direct, fast access to rows. Oracle Database supports several types of index:
Normal indexes. (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 indexes, which are based on expressions. They enable you to construct queries that evaluate the value returned by an expression, which in turn may include built-in or user-defined functions.
Domain indexes, which are instances of an application-specific index of type indextype
42 | CREATING INDEX in Oracle SQL | Oracle PL/SQL Programming
#index #oraclesql #oracle_sql_index #table_index
