Child Table

A child table is the leaf of a joined set of tables used in a joined search. In Joins Example, "Addresses" and "Phones" are child tables because the link is from the records of the "Addresses" and "Phones" tables to the records of the "Persons" table. In TIBCO Patterns - Search, a table must be designated as a child table when it is created. The parent table of the child table is specified at the time it is created and is fixed for the life of the table and cannot be modified.

•

The relationship between child and parent tables is between physical tables, not table names. Renaming either the child table or parent table doesn’t alter the relationship between them.

•

In TIBCO Patterns - Search a child table cannot be a parent table.

•

You cannot have a child table without a parent table.

•

Regular searches can be performed on a child table. A child table is also a standard table and in most respects behaves like a standard table.

Special considerations are involved when using a predicate index on a child table. For more information about predicate indexes and memory usage, see Predicate Indexes and Joined Searches.

Considerations

The roles of tables are fixed at the time they are created. Therefore, a table might have only one role. There are restrictions on the types of join relations that are supported. Only a star schema join relationship is supported. That is, one parent table with any number of child tables. Cascading and many-to-many schemas are not supported.