News & Events
[DB Seminar] Spring 2016: Daniel Chino
Finding previously unknown patterns that frequently occur on time series is a core task of mining time series. These patterns are known as time series motifs and are essential to associate events and meaningful occurrences within the time series. In this work we propose a method based on a trie data structure, that allows a fast and accurate time series motif discovery. From the experiments performed on synthetic and real data we can see that our TrieMotif approach is able Read More
[DB Seminar] Fall 2015: Yifei Ma
Many modern information access problems involve highly complex patterns that cannot be handled by traditional keyword based search. Active Search is an emerging paradigm that helps users quickly find relevant information by efficiently collecting and learning from user feedback. We consider active search on graphs, where the nodes represent the set of instances users want to search over and the edges encode pairwise similarity among the instances. Existing active search algorithms are either short of theoretical guarantees or inadequate for Read More
[DB Seminar] Fall 2015: Huanchen Zhang
Using indexes for query execution is crucial for achieving high performance in modern on-line transaction processing databases. For a main-memory database, however, these indexes consume a large fraction of the total memory available and are thus a major source of storage overhead of in-memory databases. To reduce this overhead, we propose using a two-stage index: The first stage ingests all incoming entries and is kept small for fast read and write operations. The index periodically migrates entries from the first Read More
[DB Seminar] Fall 2015: Zeyuan Shang
Finding real-world applications and workloads is the bane of every database researcher. To overcome this problem, we present the Carnegie Mellon Database Application Catalog (DBAC). The DBAC finds database applications from on-line source code repositories (e.g., GitHub) and then automatically installs them in a virtual machine sandbox. It then submits requests to the application that cause it to interact with a database. The DBAC monitors all database queries the application invokes and stores them in a central repository for analysis. Read More
[DB Seminar] Fall 2015: Bryan Hooi / Hyun Ah Song
Suppose you are a teacher, and have to convey a set of object-property pairs (‘lions eat meat’; or ‘aspirin is a blood- thinner’). A good teacher will convey a lot of information, with little effort on the student side. Specifically, given a list of objects (like animals or medical drugs) and their associated properties, what is the best and most intuitive way to convey this information to the student, without the student being overwhelmed? A related, harder problem is: how Read More
[DB Seminar] Fall 2015: Prashanth Menon
Modern write-intensive key-value stores have emerged as the prevailing data storage system for many big applications. However, these systems often sacrifice their read performance to cope with high data ingestion rates. Solid-state drives (SSD) can lend their help, but their limited capacity and their peculiar characteristics make their exclusive use uneconomical. Hence, hybrid storage environments with both SSDs and hard-disk drives (HDD) present interesting research opportunities for optimization. In this work, we first present an analytical cost model to predict Read More
Summer 2016 Research Internships
The Carnegie Mellon Database Group is offering multiple internship positions for a special summer research project at its Pittsburgh, Pennsylvania campus. It will be an intense 12-week internship from June to August 2016. The project will be to work on a new open-source distributed database system from scratch. Thus, we are looking for candidates that have strong systems-level C/C++ programming skills. Interns will be paid a three-month summer salary (commensurate with skills and experience) and the cost of travel expenses. Read More
Danai’s dissertation wins multiple distinctions!
Danai's dissertation won both the nomination for the ACM Doctoral Dissertation award, as well as one of the three Honorable mentions for the SCS Doctoral Dissertation award. CMU/SCS is allowed to nominate two dissertations for the ACM award. The full announcement by the Dean is below: We are pleased to give you the 2015 selections for the SCS/ECE Nominations to ACM for the Doctoral Dissertation Award and the winner of the SCS Doctoral Dissertation award for 2015: ACM Nomination & Read More