3,270 Hits in 4.6 sec

Robustness against Read Committed for Transaction Templates [article]

Brecht Vandevoort, Bas Ketsman, Christoph Koch, Frank Neven
2021 arXiv   pre-print
Robustness testing and safely executing transactions under the lower isolation level RC can therefore provide a direct way to increase transaction throughput without changing DBMS internals.  ...  The isolation level Multiversion Read Committed (RC), offered by many database systems, is known to trade consistency for increased transaction throughput.  ...  the lower isolation level RC.  ... 
arXiv:2107.12239v1 fatcat:b4knmi52fvgiladm6vhcfneyfe

Robustness of Quantum-Enhanced Adaptive Phase Estimation [article]

Pantita Palittapongarnpim, Barry C. Sanders
2018 arXiv   pre-print
As all physical adaptive quantum-enhanced metrology schemes operate under noisy conditions with only partially understood noise characteristics, so a practical control policy must be robust even for unknown  ...  We aim to devise a test to evaluate the robustness of AQEM policies and assess the resource used by the policies.  ...  This limit also appears at V = 7 for log-normal noise, whereas the same noise-level only lead to ℘ B approaching SQL when skew-normal noise is present.  ... 
arXiv:1809.05525v2 fatcat:2o6dyvlnvbb4bh7lbeu7ykpgaa

Not for the timid

Willis Lang, Karthik Ramachandra, David J. DeWitt, Shize Xu, Qun Guo, Ajay Kalhan, Peter Carlin
2016 Proceedings of the VLDB Endowment  
Increased sensitivity to idleness leads to aggressive over-booking while the converse leads to conservative reclamation and lower utilization levels.  ...  To help us answer these questions, we used production user activity traces from Azure SQL DB and built models of an over-booking mechanism.  ...  ACKNOWLEDGEMENTS The authors would like to thank Rohan Kumar and Mike Zwilling for their support and Jignesh Patel, Alan Halverson, Eric Robinson, Rimma Nehme, Raghu Ramakrishnan for their comments.  ... 
doi:10.14778/3007263.3007264 fatcat:6p4rmubc55aatejf7oxjcvl7xm

Database Versioning 2.0, a Transparent SQL Approach Used in Quantitative Management and Decision Making

Cosmin Cioranu, Marius Cioca, Carmen Novac
2015 Procedia Computer Science  
versioning system which keeps the natural dependency between data on each internal revision, a basis of security and alteration control mechanism, trend analytics, without sacrificing(within acceptable levels  ...  Also we should keep in mind that the cost per-byte and processing power, in later years, is becoming lower, for small to middle systems (e.g. small on-line shop, small to middle organization, financing  ...  The first involves employing a validation scheme (formal) and the manual engine lets the decision at application level to decide if the information stored is considered a checkpoint (e.g. valuable and  ... 
doi:10.1016/j.procs.2015.07.030 fatcat:tecklzpzy5hk3d5uyf4rce5biq

Automated Demand-driven Resource Scaling in Relational Database-as-a-Service

Sudipto Das, Feng Li, Vivek R. Narasayya, Arnd Christian König
2016 Proceedings of the 2016 International Conference on Management of Data - SIGMOD '16  
However, automating this task is daunting for most tenants since estimating resource demands for arbitrary SQL workloads in an RDBMS is complex and challenging.  ...  Our solution derives a set of robust signals from database engine telemetry and combines them to significantly improve accuracy of demand estimation for database workloads resulting in more accurate scaling  ...  Several members of the Microsoft Azure SQL Database group, including Peter Carlin, Miroslav Grbic, Veljko Vasic, and Petar Lotrean, have provided feedback that influenced our work.  ... 
doi:10.1145/2882903.2903733 dblp:conf/sigmod/DasLNK16 fatcat:khsgvr3wxrfvhhbq2qjthvesta

The Cost of Serializability on Platforms That Use Snapshot Isolation

Mohammad Alomari, Michael Cahill, Alan Fekete, Uwe Rohm
2008 2008 IEEE 24th International Conference on Data Engineering  
SI prevents many anomalies that appear in other isolation levels, but it still can result in non-serializable execution, in which database integrity constraints can be violated.  ...  However, ELM has peak performance which is similar to SI, no matter which transactions are chosen for modification. Thus we say that ELM is a robust technique for ensure serializable execution.  ...  Indeed in most SQL-based platforms, the Read Committed (abbreviated as RC) isolation level is the default, used when the application developer has not explicitly set an isolation level.  ... 
doi:10.1109/icde.2008.4497466 dblp:conf/icde/AlomariCFR08 fatcat:pxflhyepvrgixh3ssadngfm3ji

Introducing Custom Language Extensions to SQL:1999 [chapter]

Jernej Kovse, Wolfgang Mahnke
2003 Lecture Notes in Computer Science  
Even though SQL has become widely accepted as a language for implementing relational database schemas and querying data, there are cases where its users experience the need for new language abstractions  ...  This paper describes the idea of language extensions to SQL:1999 that come in form of independent packages and may be implemented by different vendors.  ...  language construct to lower level constructs that are either directly supported by SQL:1999 or need to pass additional reduction steps.  ... 
doi:10.1007/3-540-45017-3_15 fatcat:4l6sfarybfcfnngdsxqpmu2yei

SeSQLite: Security Enhanced SQLite

Simone Mutti, Enrico Bacis, Stefano Paraboschi
2015 Proceedings of the 31st Annual Computer Security Applications Conference on - ACSAC 2015  
SeSQLite implements labeling and access control at both schema level (for tables and columns) and row level. This permits the management of a fine-grained access policy for database objects.  ...  SQLite is the most widely deployed in-process library that implements a SQL database engine. It offers high storage efficiency, fast query operation and small memory needs.  ...  Schema Level All SQL statements must be compiled before their execution.  ... 
doi:10.1145/2818000.2818041 dblp:conf/acsac/MuttiBP15 fatcat:qs7inhnj7jggjax7nha4cmo6vu

Can the Elephants Handle the NoSQL Onslaught? [article]

Avrilia Floratou, Nikhil Teletia, David J. Dewitt, Jignesh M. Patel, Donghui Zhang
2012 arXiv   pre-print
We present insights from this evaluation and speculate on potential trends for the future.  ...  SQL) on two workloads (decision support analysis and interactive data-serving) that represent the two ends of the application spectrum.  ...  The read latency is significantly lower now, compared to that of the previous experiment where the "read committed" isolation level was used.  ... 
arXiv:1208.4166v1 fatcat:woqbgeo6dvdyjmd7htcr3ybgeq

Can the elephants handle the NoSQL onslaught?

Avrilia Floratou, Nikhil Teletia, David J. DeWitt, Jignesh M. Patel, Donghui Zhang
2012 Proceedings of the VLDB Endowment  
We present insights from this evaluation and speculate on potential trends for the future.  ...  SQL) on two workloads (decision support analysis and interactive data-serving) that represent the two ends of the application spectrum.  ...  The read latency is significantly lower now, compared to that of the previous experiment where the "read committed" isolation level was used.  ... 
doi:10.14778/2367502.2367511 fatcat:qqcpsgtswncqphnfrxfgiatqka

PNUTS to Sherpa

Brian F. Cooper, Ramana Yerneni, P. P. S. Narayan, Raghu Ramakrishnan, Utkarsh Srivastava, Adam Silberstein, Philip Bohannon, Hans-Arno Jacobsen, Nick Puz, Daniel Weaver
2019 Proceedings of the VLDB Endowment  
As bigger applications started using Sherpa, we decided to build isolation mechanisms into the multi-tenant hosted architecture.  ...  Instead, mastership is assigned at the tablet level.  ... 
doi:10.14778/3352063.3352146 fatcat:u6ysd7sza5fojo2trusnt2sfdy

DBaaS Multitenancy, Auto-tuning and SLA Maintenance in Cloud Environments: a Brief Survey

Vinicius Da Silveira Segalin, Carina Friedrich Dorneles, Mario Antonio Ribeiro Dantas
2018 iSys  
agreed between client and provider, that are defined in the Service Level Agreement (SLA).  ...  In this paper it is presented a classification based on three main parameters that aim to manage resources for enhancing the performance on DBaaS and guarantee that the SLA is respected for both user and  ...  There are several types of multitenancy providing different levels of isolation [24, 4] , and for each isolation level a different abstraction will be given to the tenant.  ... 
doi:10.5753/isys.2018.362 fatcat:gjwho257wra6pcdwnpx6wcsyja

Coordination through querying in the youtopia system

Nitin Gupta, Lucja Kot, Gabriel Bender, Sudip Roy, Johannes Gehrke, Christoph Koch
2011 Proceedings of the 2011 international conference on Management of data - SIGMOD '11  
On one hand, entangled queries are simpler to use than lower-level coordination constructs offered by operating systems; on the other, they support many interesting use cases.  ...  A query whose postcondition is not satisfied is not rejected but waits for an opportunity to retry. We believe that Youtopia captures coordination at the ideal level of abstraction [3] .  ... 
doi:10.1145/1989323.1989490 dblp:conf/sigmod/GuptaKBRGK11 fatcat:lsfvnglysfbkpdg3djhygzyqt4

DoubleGuard: Detecting Intrusions in Multitier Web Applications

Meixing Le, Angelos Stavrou, Brent ByungHoon Kang
2012 IEEE Transactions on Dependable and Secure Computing  
Finally, using DoubleGuard, we were able to expose a wide range of attacks with 100% accuracy while maintaining 0% false positives for static web services and 0.6% false positives for dynamic web services  ...  For a regular user, the web request r u will trigger the set of SQL queries Q u ; for an administrator, the request r a will trigger the set of admin level queries Q a .  ...  With a more accurate model, we can reach 100% sensitivity with a lower False Positive rate.  ... 
doi:10.1109/tdsc.2011.59 fatcat:u3vwuq5yavggpgm542glsfwpvq

Automatically Indexing Millions of Databases in Microsoft Azure SQL Database

Sudipto Das, Surajit Chaudhuri, Miroslav Grbic, Igor Ilic, Isidora Jovandic, Andrija Jovanovic, Vivek R. Narasayya, Miodrag Radulovic, Maja Stikic, Gaoxiang Xu
2019 Proceedings of the 2019 International Conference on Management of Data - SIGMOD '19  
Our service has been generally available for more than two years, generating index recommendations for every database in Azure SQL Database, automatically implementing them for a large fraction, and significantly  ...  We describe the challenges, architecture, design choices, implementation, and learnings from building an industrial-strength auto-indexing service for Microsoft Azure SQL Database, a relational database  ...  ACKNOWLEDGMENTS We thank the entire auto tuning engineering team in Azure SQL Database for their contributions to the auto-indexing service.  ... 
doi:10.1145/3299869.3314035 dblp:conf/sigmod/DasGIJJNRSXC19 fatcat:ecpfvrs7r5b5xedc7ktbvgdhyy
« Previous Showing results 1 — 15 out of 3,270 results