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Creating and Managing Volatile Index
Creating and Managing Volatile Index
Create and Use Index
The volatile table provides a RED-BLACK Tree optimized for real-time search. Indexes can be set for all data types. However, one index can be created for one column, and no composite index is provided.
Mach> create volatile table vtable (id integer, name varchar(10)); Created successfully. Mach> create index idx_vrb on vtable (name) index_type redblack; Created successfuly. Mach> desc vtable; ---------------------------------------------------------------- NAME TYPE LENGTH ---------------------------------------------------------------- ID integer 11 NAME varchar 10 [ INDEX ] ---------------------------------------------------------------- NAME TYPE COLUMN ---------------------------------------------------------------- IDX_VRB REDBLACK NAME iFlux>
Primary Key Index
When a primary key is assigned to a specific column of a volatile table, a RED-BLACK Tree index is automatically generated. In this case, a special index with a Uniqueness attribute is created and does not allow duplicate values.
Mach> create volatile table vtable (id integer primary key, name varchar(20)); Created successfully. Mach> desc vtable; ---------------------------------------------------------------- NAME TYPE LENGTH ---------------------------------------------------------------- ID integer 11 NAME varchar 20 [ INDEX ] ---------------------------------------------------------------- NAME TYPE COLUMN ---------------------------------------------------------------- __PK_IDX_VTABLE REDBLACK ID iFlux>
Other Index Types
The bitmap or keyword index used in the log table can not be used in a volatile table.
Mach> create bitmap index idx_1237 on vtable(id1); [ERR-02069 : Error in index for invalid table. BITMAP Index can only be created for LOG Table.] Mach> create keyword index idx_1238 on vtable(name); [ERR-02069 : Error in index for invalid table. KEYWORD Index can only be created for LOG Table.]