User-deened aggregates can be the linchpin of sophisticated datamining functions and other advanced database applications. This is demonstrated by our eecient implementation on DB2 of SQL3 user-deened aggregates extended with early returns, which we have used to implement several data mining algorithms. Aggregates with early returns are monotonic and can thus be used freely in recursive queries.

Previous research in visual query languages has fo-cused on pre-deened visual representations of data and queries, which are suitable for speciic applications, but diicult to extend and generalize. In this paper we propose a metalanguage to query an object-oriented database with user-deened pictures. By manipulating these pictures, the user can extract information about the data in a purely vis...

We analyse the detailed structure of a highly-inclined (i & 80◦) disc galaxy which lies within the Hubble Ultra Deep Field (UDF). The unprecedented depth of the UDF data allow disc and extraplanar emission to be reliably traced to surface brightness levels of μV,i,z ∼ 29 − 30 mag arcsec −2 (corresponding to rest-frame equivalents of μg,r,i ∼ 28 − 29 mag arcsec ) in this redshift z = 0.32 system...

This note proposes a notion of user-defined literals based on literal constructors without requiring new syntax. If combined with the separate proposal for generalized initializer lists, it becomes a generalization of the C99 notion of compound literals. Basically, a constructor defines a user-defined literal if it is inline and specifies a simple mapping of its arguments to object representati...

With the aim of audiovisual database consulting, the prospect of an interactive visual organization tool should be enviable. We consider a document as a visual entity in a computer screen. Thanks to an appropriate simplified GUI, a user can organize a few documents. Its notion of audiovisual similarity is relative to the Euclidean distance between entities: the more they are close, the more the...

String data is ubiquitous, and its management has taken on particular importance in the past few years. Approximate queries are very important on string data. This is due, for example, to the prevalence of typographical errors in data, and multiple conventions for recording attributes such as name and address. Commercial databases do not support approximate string queries directly, and it is a ...