Real-world objects are inherently spatially and temporally referenced, and many database applications rely on databases that record the past, present, and anticipated future locations of, e.g., people or land parcels. As a result, indices that efficiently support queries on the spatio-temporal extents of objects are needed. In contrast, past indexing research has progressed in largely separate ...

In applications like nancial trading, scheduling, manufacturing and process control, time based predicates in queries and rules are very important. There is also a need to de ne sets of time points or intervals. We refer to these sets as calendars. This paper presents a system of calendars that allows speci cation of natural-language time-based expressions, maintenance of valid time in database...

The bitemporal conceptual data model proposed for handling time within the framework of relational data model can be eflcctiuely represented using valid-time and transaction-time intervals as time-stamps on tuples. We observe that in many real-world applications, valid-time interval for a fact is not known completely while entering the fact in a temporal database. The model provides ‘open’ inte...

A standard relation has two dimensions: attributes and tuples. A temporal relation contains two additional orthogonal time dimensions, namely, valid time and transaction time. Valid time records when facts are true in the modeled reality, and transaction time records when facts are stored in the temporal relation. Although, in general, there are no restrictions between the valid time and transa...

Application development on top of database systems is heavily based on the existence of embedded and 4GL languages. However, the issue of designing and implementing embedded or 4GL temporal languages has not been addressed insofar. In this paper, we present a design approach for implementing an embedded temporal language that supports valid time. Furthermore, we introduce implementation techniq...

Most data managed by existing, real-world database applications is time referenced. Data warehouses are good examples. Often, two temporal aspects of data are of interest, namely valid time, when data is true in the mini-world, and transaction time, when data is current in the database, resulting in so-called bitemporal data. Like spatial data, bitemporal data thus has associated two-dimensiona...

Schema evolution is the ability of the database to respond to changes in the real world by allowing the schema to evolve. The multidimensional conditionally evolving schema(MD-CES) is a conceptual model for conditional schema changes, which modify the schema of those tuples that satisfy the change condition. The MD-CES is lossless and preserves schemas, but has an exponential space complexity. ...

We consider the problem of measuring statistical evidence against a composite null hypothesis. base our approach on concept an E-value, which measures by multiplication factor achieved engaging in bets that are fair under null. adopt log-optimality criterion for choosing among all possible E-values, was considered earlier fixed sample size. extend these ideas to sequential testing optional stop...