Publications de Manoussos Gavriil Athanassoulis

Adaptive partitioning and indexing for in situ query processing

Anastasia Ailamaki, Manoussos Gavriil Athanassoulis, Ioannis Alagiannis, Matthaios Alexandros Olma, Manolis Karpathiotakis

The constant flux of data and queries alike has been pushing the boundaries of data analysis systems. The increasing size of raw data files has made data loading an expensive operation that delays the data-to-insight time. To alleviate the loading cost, in ...

SPRINGER2020

Slalom: Coasting Through Raw Data via Adaptive Partitioning and Indexing

Anastasia Ailamaki, Manoussos Gavriil Athanassoulis, Ioannis Alagiannis, Matthaios Alexandros Olma, Manolis Karpathiotakis

The constant flux of data and queries alike has been pushing the boundaries of data analysis systems. The increasing size of raw data files has made data loading an expensive operation that delays the data-to-insight time. Hence, recent in-situ query proce ...

VLDB Endowment2017

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

BF-Tree: Approximate Tree Indexing

Anastasia Ailamaki, Manoussos Gavriil Athanassoulis

The increasing volume of time-based generated data and the shift in storage technologies suggest that we might need to reconsider indexing. Several workloads - like social and service monitoring - often include attributes with implicit clustering because o ...

2014

Solid-State Storage and Work Sharing for Efficient Scaleup Data Analytics

Manoussos Gavriil Athanassoulis

Today, managing, storing and analyzing data continuously in order to gain additional insight is becoming commonplace. Data analytics engines have been traditionally optimized for read-only queries assuming that the main data reside on mechanical disks. The ...

EPFL2014

Reactive and Proactive Sharing Across Concurrent Analytical Queries

Anastasia Ailamaki, Manoussos Gavriil Athanassoulis, Iraklis Psaroudakis, Matthaios Alexandros Olma

Today an ever increasing amount of data is collected and analyzed by researchers, businesses, and scientists in data warehouses (DW). In addition to the data size, the number of users and applications querying data grows exponentially. The increasing concu ...

2014

Scaling up analytical queries with column-stores

Anastasia Ailamaki, Manoussos Gavriil Athanassoulis, Ioannis Alagiannis

As data analytics is used by an increasing number of applications, data analytics engines are required to execute workloads with increased concurrency, i.e., an increasing number of clients submitting queries. Data management systems designed for data anal ...

2013

Sharing Data and Work Across Concurrent Analytical Queries

Anastasia Ailamaki, Manoussos Gavriil Athanassoulis, Iraklis Psaroudakis

Today's data deluge enables organizations to collect massive data, and analyze it with an ever-increasing number of concurrent queries. Traditional data warehouses (DW) face a challenging problem in executing this task, due to their query-centric model: ea ...

2013

Querying Persistent Graphs using Solid State Storage

Manoussos Gavriil Athanassoulis

Recent advances in solid state technology have led to the introduction of Solid State Drives (SSDs). Todays SSDs store data persistently using NAND flash memory. While SSDs are more expensive than hard disks when measured in dollars per gigabyte, they are ...

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

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