|
|
|
A Virtual Table is operated upon as an ordinary c-treeDB table (with a few limitations, depending on the type of the Virtual Table, see Unsupported Functions for details). However, it is not an actual physical table; it is an “interpretation” of the records (some or all) within the host (parent) table. Virtual Tables can be thought of as a generic concept. Actual implementations of this concept are the Virtual Table types, which are currently implemented through the MultiRecordTable type.
A Virtual Table is identified in the c-treeDB database dictionary as a particular marker indicating the type of Virtual Table. The dictionary handling function has been modified to differentiate Virtual Tables from regular tables and also make the c-treeDB interface view a Virtual Table as a regular table. For instance, when listing tables of a dictionary, Virtual Tables are listed together along with regular tables. Once created, a Virtual Table is operated upon as any other c-treeDB table.
