Method for loading rows into a database table while enforcing constraints

摘要

Data to be loaded into a table of a database is read from an input file by a LOAD utility including a CHECK subutility that performs constraint checking on each row prior to loading the row into the table. During initialization of the CHECK subutility, the DB2 catalog is read to identify any constraints that apply to the data to be loaded. If any check constraints apply, check constraint routines are built and compiled by the CHECK subutility. If any referential integrity constraints apply, the key values for the parent index of each referential integrity constraint are read and stored in an additional dataspace allocated by the CHECK subutility so that the foreign key values from each row to be loaded can be located by the CHECK subutility and compared against the parent index values prior to loading the data into the table. When the constraint checking for the loading of data is complete, the additional dataspace allocated by the CHECK subutility is released.