Physical Database DDL Statements › Naming Conventions › Entity Currency

Entity Currency

Entities That Establish Currency

The DMCL, SEGMENT, and DBTABLE entities establish currency for associated entities, as shown in the following table:

How Is Currency Established?

Currency is established when you:

• Perform a CREATE or ALTER operation on a DMCL, SEGMENT, or DBTABLE entity occurrence
• Fully qualify the name of an entity associated with a DMCL, segment, or database name table on a CREATE, ALTER, or DROP statement

Subsequent operations on associated entities are applied to that particular DMCL, segment, or database name table. The following example establishes IDMSDMCL as the current DMCL occurrence. The database buffer statement that follows implicitly associates the named buffer with IDMSDMCL:

alter dmcl idmsdmcl;

create buffer index_buffer
  page size 1076
  local mode buffer pages 10
  central version buffer
    initial pages 100
    maximum pages 500;

Use Fully-qualified Names if Currency Not Established

If you don't establish currency on a DMCL, segment, or database name table before operating on an associated entity, you must qualify the name of the associated entity with the name of the DMCL, segment, or database name table. In the following example, the BUFFER statement must qualify the named buffer with the name of the DMCL because DMCL currency was not first established:

create buffer idmsdmcl.index_buffer
  page size 1076
  local mode buffer pages 10
 .
 .
 .

Once this statement is executed, IDMSDMCL is established as the current DMCL.