Oliver John Kennedy

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Applications ranging from algorithmic trading to scientific data analysis require real-time analytics based on views over databases receiving thousands of updates each second. Such views have to be kept fresh at millisecond latencies. At the same time, these views have to support classical SQL, rather than window semantics, to enable applications that(More)
Estimation via sampling out of highly selective join queries is well known to be problematic, most notably in online aggregation. Without goal-directed sampling strategies, samples falling outside of the selection constraints lower estimation efficiency at best, and cause inaccurate estimates at worst. This problem appears in general probabilistic database(More)
Security modifications to legacy network protocols are expensive and disruptive. This paper outlines an approach, based on external security monitors, for securing legacy protocols by deploying additional hosts that locally monitor the inputs and outputs of each host executing the protocol, check the behavior of the host against a safety specification, and(More)
We discuss a multi-objective/goal programming model for the allocation of inventory of graphical advertisements. The model considers two types of campaigns: guaranteed delivery (GD), which are sold months in advance, and non-guaranteed delivery (NGD), which are sold using real-time auctions. We investigate various advertiser and publisher objectives such as(More)
Three mentalities have emerged in analytics. One view holds that reliable analytics is impossible without high-quality data, and relies on heavy-duty ETL processes and upfront data curation to provide it. The second view takes a more ad-hoc approach, collecting data into a data lake, and placing responsibility for data quality on the analyst querying it. A(More)
Probabilistic databases, in particular ones that allow users to externally define models or probability distributions -- so called VG-Functions -- are an ideal tool for constructing, simulating and analyzing hypothetical business scenarios. Enterprises often use such tools with parameterized models and need to explore a large parameter space in order to(More)
Embedded database engines such as SQLite provide a convenient data persistence layer and have spread along with the applications using them to many types of systems, including interactive devices such as smartphones. Android, the most widely-distributed smartphone platform, both uses SQLite internally and provides interfaces encouraging apps to use SQLite(More)
Genital herpes is one of the commonest sexually transmitted infections worldwide. Using the best available evidence, this guideline recommends strategies for diagnosis, management, and follow-up of the condition as well as for minimising transmission. Early recognition and initiation of therapy is key and may reduce the duration of illness or avoid(More)
External security monitors (ESMs) are a new network component for securing legacy protocols without requiring modifications to existing hardware, software, or the protocol. An ESM is an additional host that checks each message sent by a legacy host against a safety specification. ESMs use trusted hardware to assure remote principals that the safety(More)