Richard Snodgrass

• University of Arizona

We describe the Arizona-NOIRLab Temporal Analysis and Response to Events System (ANTARES), a software instrument designed to process large-scale streams of astronomical time-domain alerts. With the advent of large-format CCDs on wide-field imaging telescopes, time-domain surveys now routinely discover tens of thousands of new events each night, mor...

We describe the Arizona-NOIRLab Temporal Analysis and Response to Events System (ANTARES), a software instrument designed to process large-scale streams of astronomical time-domain alerts. With the advent of large-format CCDs on wide-field imaging telescopes, time-domain surveys now routinely discover tens of thousands of new events each night, mor...

Leveraging existing data sources to improve the declaration and management of authorship conflicts of interest.

Modern DBMSes are designed to support many transactions running simultaneously. DBMS thrashing is indicated by the existence of a sharp drop in transaction throughput. Thrashing behavior in DBMSes is a serious concern to database administrators (DBAs) as well as to DBMS implementers. From an engineering perspective, therefore, it is of critical imp...

The Arizona-NOAO Temporal Analysis and Response to Events System (ANTARES) is a joint effort of NOAO and the Department of Computer Science at the University of Arizona to build prototype software to process alerts from time-domain surveys, especially LSST, to identify those alerts that must be followed up immediately. Value is added by annotating...

It is surprisingly hard to obtain accurate and precise measurements of the time spent executing a query because there are many sources of variance. To understand these sources, we review relevant per-process and overall measures obtainable from the Linux kernel and introduce a structural causal model relating these measures. A thorough correlationa...

The Arizona-NOAO Temporal Analysis and Response to Events System (ANTARES) is a joint effort of NOAO and the Department of Computer Science at the University of Arizona to build prototype software to process alerts from time-domain surveys, especially LSST, to identify those alerts that must be followed up immediately. Value is added by annotating...

Recruitment and retention of women has been a persistent problem in the field of computer science. With a growing number of jobs that require a computer science degree, this problem does not only affect computer science departments with low enrollment, but also impacts industry. There is still no universally accepted explanation for the underrepres...

Software engineering frameworks tame the complexity of large collections of classes by identifying structural invariants, regularizing interfaces, and increasing sharing across the collection. We wish to appropriate these benefits for families of closely related benchmarks, say for evaluating query engine implementation strategies. We introduce the...

The Arizona-NOAO Temporal Analysis and Response to Events System (ANTARES) is a joint project of the National Optical Astronomy Observatory and the Department of Computer Science at the University of Arizona. The goal is to build the software infrastructure necessary to process and filter alerts produced by time-domain surveys, with the ultimate so...

In the database field, while very strong mathematical and engineering work has been done, the scientific approach has been much less prominent. The deep understanding of query optimizers obtained through the scientific approach can lead to better engineered designs. Unlike other domains, there have been few DBMS-dedicated laboratories, focusing on...

Where does computer science as an intellectual discipline fit in human discourse? Over a dozen contributors have looked at this question of identity from as many viewpoints. In this closing statement, we emphasize six themes running through these 16 commentaries and draw some conclusions that seem to be supported by the symposium.

Time provides context for all our experiences, cognition, and coordinated collective action. Prior research in linguistics, artificial intelligence, and temporal databases suggests the need to differentiate between temporal facts with goal-related semantics (i.e., telic) from those are intrinsically devoid of culmination (i.e., atelic). To differen...

In the database field, while very strong mathematical and engineering work has been done, the scientific approach has been much less prominent. The deep understanding of query optimizers obtained through the scientific approach can lead to better engineered designs. Unlike other domains, there have been few DBMS-dedicated laboratories, focusing on...

Computer science is often divided into two camps, systems and theory, but of course the reality is more complicated and more interesting than that. One example is the area of "experimental algorithmics," also termed "empirical algorithmics." This fascinating discipline marries algorithm analysis, which is often done with mathematical proofs, with e...

Valid-time indeterminacy is "don't know when" indeterminacy, coping with cases in which one does not exactly know when a fact holds in the modeled reality. In this paper, we first propose a reference representation (data model and algebra) in which all possible temporal scenarios induced by valid-time indeterminacy can be extensionally modeled. We...

It is surprisingly hard to obtain accurate and precise measurements of the time spent executing a query. We review relevant process and overall measures obtainable from the Linux kernel and introduce a structural causal model relating these measures. A thorough correlational analysis provides strong support for this model. Using this model, we deve...

In this article we present refinements on previously proposed approaches to forensic analysis of database tampering. We significantly generalize the basic structure of these algorithms to admit new characterizations of the “where” axis of the corruption diagram. Specifically, we introduce page-based partitioning as well as attribute-based partition...

Until 2000, computer science enrollments were steadily increasing. Then suddenly students started turning to other fields; by 2008, enrollments had dropped by 50 percent. To that end, Jan Cuny has been leading a program at the National Science Foundation to increase both the number and diversity of students in computing. In this interview with Ubiq...

Information restriction controls access and renders records immutable; information accountability requires data transparency to easily and efficiently determine when a particular use is appropriate. Information accountability in the context of relational databases is associated with time in a surprising number of ways, as is summarized in this pape...

If past versions of XML documents are retained, what of the various integrity constraints defined in XML Schema on those documents? This paper describes how to interpret such constraints as sequenced constraints, applicable at each point in time. We also consider how to add new variants that apply across time, so-called non-sequenced constraints. O...

Database management systems (DBMSes) form a cornerstone of modern IT infrastructure, and it is essential that they have excellent performance. Much of the work to date on optimizing DBMS performance has emphasized ensuring efficient data access from secondary storage. This paper shows that DBMSes can also benefit significantly from dynamic code spe...

We show how to extend temporal support of SQL to the Turing-complete portion of SQL, that of persistent stored modules (PSM). Our approach requires minor new syntax beyond that already in SQL/Temporal to define and to invoke PSM procedures and functions, thereby extending the current, sequenced, and non-sequenced semantics of queries to such routin...

Relational database management systems are general in the sense that they can handle arbitrary schemas, queries, and modifications, this generality is implemented using runtime metadata lookups and tests that ensure that control is channelled to the appropriate code in all cases. Unfortunately, these lookups and tests are carried out even when info...

Regulations and societal expectations have recently emphasized the need to mediate access to valuable databases, even access by insiders. Fraud occurs when a person, often an insider, tries to hide illegal activity. Companies would like to be assured that such tampering has not occurred, or if it does, that it will be quickly discovered and used to...

Relational database management systems support a wide variety of data types and operations. Such generality involves much branch condition checking, which introduces inefficiency within the query evaluation loop. We previously introduced micro-specialization, which improves performance by eliminating unnecessary branching statements and the actual...

Regulations and societal expectations have recently emphasized the need to mediate access to valuable databases. Fraud occurs when a person (mostly an insider) tampers illegally with a database. Data owners would like to be assured that such tampering has not occurred, or if it does, that it will be quickly discovered. The problem is exacerbated wi...

Software developers should use empirical methods to analyze their designs to predict how working systems will behave.

Melanie Mitchell, a Professor of Computer Science at Portland State University and an External Professor at the Santa Fe Institute, has written a compelling and engaging book entitled Complexity: A Guided Tour, published just last year by Oxford University Press. This book was named by Amazon.com as one of the 10 best science books of 2009. Her res...

Valid-time indeterminacy concerns not knowing exactly when a fact holds in the modeled reality. In this paper, we first propose a reference approach (data model and algebra) in which all possible temporal scenarios induced by valid-time indeterminacy can be extensionally modeled. We then specify a family of sixteen more compact representational dat...

Tampering of a database can be detected through the use of cryptographically strong hash functions. Subsequently, applied forensic analysis algorithms can help determine when, what, and perhaps ultimately who and why. This paper presents a novel forensic analysis algorithm, the tiled Bitmap algorithm, which is more efficient than prior forensic ana...

If computer science is to truly become a "science," as Newell, Perlis, and Simon originally conceived, then it must integrate three equally ascendant perspectives: mathematics, science, and engineering. The scientific perspective can help us to understand computational tools and computation itself, through the articulation of enduring, technology-i...

Spurred by financial scandals and privacy concerns, governments worldwide have moved to ensure confidence in digital records by regulating their retention and deletion. These requirements have led to a huge market for compliance storage servers, which ensure that data are not shredded or altered before the end of their mandatory retention period. T...