ABSTRACT
Temporal databases attempt to optimize the join between a fact row with a single event date and a dimension table with two date columns that form an interval. The relational integrity issues and relational integrity constraints work together to render the task of managing time variant data even more difficult than it was for a nontemporal Relational Database Management System (RDBMS). The confusing query languages, none of which has yet been declared the standard, render the task of querying time variant data more difficult than it was for a nontemporal RDBMS. The set logic inherent in every RDBMS causes each row of a fact table to join to all the rows of a dimension table for a given primary key. In the process, temporal databases actually increase the workload on the RDBMS as it enforces relational integrity constraints to avoid relational integrity issues in the temporal database. The temporal query languages are confusing and, as yet, not standardized.
