Oracle's indexes can be grouped into 5 categories, including unique indexes, combined indexes, reverse key indexes, bitmap indexes, and function based indexes.
1. Standard syntax for creating indexes
The following refers to the content:
CREATE index index name on table name (column name)
tablespace table space name;
For example:
The following refers to the content:
CREATE INDEX idx_of_imsi on Uim_auth_file (IMSI) tablespace users;
2. Create a unique index
The following are references:
CREATE unique index index name on table name (column name)
tablespace table space name;
For example:
The following refers to the content:
CREATE UNIQUE INDEX idx_of_imsi on Uim_auth_file (IMSI) tablespace users;
3. Create a composite index
The following refers to the content:
CREATE index index name on table name (column name 1, column name 2)
tablespace table space name;
For example:
The following refers to the content:
CREATE INDEX idx_of_imsi on Uim_auth_file (iccid,imsi) tablespace users;
4. Create Reverse key index
The following refers to the content:
CREATE index index name on table name (column name) reverse
tablespace table space name;
For example:
The following refers to the content:
CREATE INDEX idx_of_imsi on Uim_auth_file (IMSI) reverse tablespace users;