Prefix Tables

For each schema format, the system creates a PREFIX_FACT table that contains keys to the dimension tables and one data field. The system also creates PREFIX_DIMENSION tables, HFM_EA_EXTRACT table to track extract timestamps for metadata, and a PREFIX_LOCK_ACCESS table to track writer and reader locks. A writer lock is used when metadata is being changed, for example, when the create or replace process is being used. A reader lock is used when metadata is not being changed and the system is updating data in the FACT table, for example when an update process is being used. These rules are used for the lock process:

Only one writer at a time can execute against the same prefix on the same DBMS instance.
If a writer is executing or is in the queue, no readers can execute until the writer has completed.
Multiple readers can execute simultaneously regardless of the point of view.
Note:
The system creates two tables for the Entity dimension: PREFIX_ENTITY and PREFIX_PARENT.

For the SQL and Essbase Aggregation Schema format, the system also creates PREFIX_DIMENSION_BASE tables.

For the Warehouse Normalized Hierarchy Schema format, the system creates PREFIX_DIMENSION_PARENT tables.

Note:

Base and Parent tables are not created for the View, Year, and Parent dimensions.

For example, if the Relational Table Prefix is DEMO, the system creates these tables for the Essbase format:

HFM_EA_EXTRACT1
HFM_LOCK_ACCESS1
DEMO_FACT
DEMO_YEAR
DEMO_VIEW
DEMO_PARENT
DEMO_SCENARIO and DEMO_SCENARIO_BASE
DEMO_PERIOD and DEMO_PERIOD_BASE
DEMO_VALUE and DEMO_VALUE_BASE
DEMO_ENTITY and DEMO_ENTITY_BASE
DEMO_ICP and DEMO_ICP_BASE
DEMO_ACCOUNT and DEMO_ACCOUNT_BASE
DEMO_CUSTOM and DEMO_CUSTOM_BASE