Caetano Sauer

Learn More
The MapReduce (MR) framework has become a standard tool for performing large batch computations—usually of aggregative nature—in parallel over a cluster of commodity machines. A significant share of typical MR jobs involves standard database-style queries, where it becomes cumbersome to specify map and reduce functions from scratch. To overcome this burden,(More)
The introduction of MapReduce as a tool for Big Data Analytics, combined with the new requirements of emerging application scenarios such as the Web 2.0 and scientific computing, has motivated the development of data processing languages which are more flexible and widely applicable than SQL. Based on the Big Data context, we discuss the points in which SQL(More)
The XQuery language was initially developed as an SQL equivalent for XML data, but its roots in functional programming make it also a perfect choice for processing almost any kind of structured and semi-structured data. Apart from standard XML processing, however, advanced language features make it hard to efficiently implement the complete language for(More)
Traditional theory and practice of write-ahead logging and of database recovery techniques revolve around three failure classes: transaction failures resolved by rollback; system failures (typically software faults) resolved by restart with log analysis, " redo, " and " undo " phases; and media failures (typically hardware faults) resolved by restore(More)
Instant recovery improves system availability by reducing the mean time to repair, i.e., the interval during which a database is not available for queries and updates due to recovery activities. Variants of instant recovery pertain to system failures, media failures, node failures, and combinations of multiple failures. After a system failure, instant(More)
Ich versichere hiermit, dass ich die vorliegende Masterarbeit mit dem Thema " Evaluation of fine-grained locking in XML databases " selbstständig verfasst und keine anderen als die angegebenen Hilfsmittel benutzt habe. Die Stellen, die anderen Werken dem Wortlaut oder dem Sinn nach entnommen wurden, habe ich durch die Angabe der Quelle, auch der benutzten(More)
Using NoSQL stores as storage layer for the execution of declarative query processing using XQuery provides a high-level interface to process data in an optimized manner. The term NoSQL refers to a plethora of new stores which essentially trades off well-known ACID properties for higher availability or scalability, using techniques such as eventual(More)