Efficient temporal join processing using time index

Time is an attribute of all real-world phenomena and many real-world database applications naturally involve time-varying information. As in traditional databases, joins are the most important and costly operators in temporal databases. Hence, efficient processing strategies for temporal joins are needed. The Entity Join operation is used to group temporal attributes of an entity into a single relation, and is important because those temporal attributes are likely to reside in separate relations due to normalization. In this paper, we propose an efficient Entity-join algorithm for both non-ordered and append-only temporal databases. The proposed approach can be applied to other temporal join operations, such as valid-time equijoin.