Publications de Radu Ioan Stoica

Manycore clique enumeration with fast set intersections

Paolo Ienne, Kubilay Atasu, Radu Ioan Stoica, Jovan Blanusa

Listing all maximal cliques of a given graph has important applications in the analysis of social and biological networks. Parallelisation of maximal clique enumeration (MCE) algorithms on modern manycore processors is challenging due to the task-level par ...

ACM2020

Online Updates on Data Warehouses via Judicious Use of Solid-State Storage

Anastasia Ailamaki, Radu Ioan Stoica, Manoussos Gavriil Athanassoulis

Data warehouses have been traditionally optimized for read-only query performance, allowing only offline updates at night, essentially trading off data freshness for performance. The need for 24x7 operations in global markets and the rise of online and oth ...

Assoc Computing Machinery2015

Flash-aware Database Transactions

Radu Ioan Stoica

Over the past 40 years, hard disks, the traditional building block of storage systems, have become increasingly slower when compared to the other system components such as the main memory and the CPU. Hard disks face mechanical constraints that cause their ...

EPFL2014

Enabling efficient OS paging for main-memory OLTP databases

Anastasia Ailamaki, Radu Ioan Stoica

Even though main memory is becoming large enough to fit most OLTP databases, it may not always be the best option. OLTP workloads typically exhibit skewed access patterns where some records are hot (frequently accessed) but many records are cold (infrequen ...

2013

Improving flash write performance by using update frequency

Anastasia Ailamaki, Radu Ioan Stoica

2013

Scalability of write-ahead logging on multicore and multisocket hardware

Anastasia Ailamaki, Radu Ioan Stoica, Frederick Ryan Johnson, Manoussos Gavriil Athanassoulis, Ippokratis Pandis

The shift to multi-core and multi-socket hardware brings new challenges to database systems, as the software parallelism determines performance. Even though database systems traditionally accommodate simultaneous requests, a multitude of synchronization ba ...

2012

MaSM: Efficient Online Updates in Data Warehouses

Anastasia Ailamaki, Radu Ioan Stoica, Manoussos Gavriil Athanassoulis

Data warehouses (DW) have been traditionally optimized for readonly query performance, allowing only offline updates at night, essentially trading off data freshness for performance. The need for 24x7 operations in global markets and the rise of online and ...

2011

Aether: A scalable approach to logging

Anastasia Ailamaki, Radu Ioan Stoica, Frederick Ryan Johnson, Manoussos Gavriil Athanassoulis, Ippokratis Pandis

The shift to multi-core hardware brings new challenges to database systems, as the software parallelism determines performance. Even though database systems traditionally accommodate simultaneous requests, a multitude of synchronization barriers serialize ...

2010

Flash in a DBMS: Where and How?

Anastasia Ailamaki, Radu Ioan Stoica, Manoussos Gavriil Athanassoulis

Over the past decade, new solid state storage technologies, with flash being the most mature one, have become increasingly popular. Such technologies store data durably, and can alleviate many handicaps of hard disk drives (HDDs). Nonetheless, they have ve ...

2010

Decoupling contention management from scheduling

Anastasia Ailamaki, Radu Ioan Stoica, Frederick Ryan Johnson

Many parallel applications exhibit unpredictable communication between threads, leading to contention for shared objects. The choice of contention management strategy impacts strongly the performance and scalability of these applications: spinning provides ...

2010

A New Look at the Roles of Spinning and Blocking

Anastasia Ailamaki, Radu Ioan Stoica, Frederick Ryan Johnson, Manoussos Gavriil Athanassoulis

Database engines face growing scalability challenges as core counts exponentially increase each processor generation, and the efficiency of synchronization primitives used to protect internal data structures is a crucial factor in overall database performa ...

2009

Evaluating and Repairing Write Performance on Flash Devices

Anastasia Ailamaki, Radu Ioan Stoica, Frederick Ryan Johnson, Manoussos Gavriil Athanassoulis

In the last few years NAND flash storage has become more and more popular as price per GB and capacity both improve at exponential rates. Flash memory offers significant benefits compared to magnetic hard disk drives (HDDs) and DBMSs are highly likely to u ...

2009