5.13 Expanding internal derived tables
HADB automatically changes query expressions containing internal derived tables and efficiently evaluates the internal derived tables. Changing query expressions containing internal derived tables is called expanding internal derived tables. For details about the rules for expanding internal derived tables, see the topic Internal derived tables in the manual HADB SQL Reference.
The priority order and selection rules for indexes that are used during retrieval are applied to the query expressions obtained after internal derived tables have been expanded. For details about the index to be used during retrieval, see 5.2 B-tree indexes and text indexes used during execution of SQL statements and 5.3 Range indexes used during execution of SQL statements.