David Lomet

The hBn-tree: A Modified hB-tree Supporting Concurrency, Recovery and Node Consolidation * (2009)

Georgios Evangelidis, David Lomet, Betty Salzberg

We describe a new access method, the hB”-tree, an adaptation of the hB-tree index to the constraints of the II-tree. The II-trees, a generalization of the Blink-trees, provide high concurrency with...

Unbundling Transaction Services in the Cloud (2009)

David Lomet, Alan Fekete, Gerhard Weikum, Mike Zwilling

The traditional architecture for a DBMS engine has the recovery, concurrency control and access method code tightly bound together in a storage engine for records. We propose a different approach,...

Unbundling Transaction Services in the Cloud (2009)

Lomet, David, Fekete, Alan, Weikum, Gerhard, Zwilling, Mike

The traditional architecture for a DBMS engine has the recovery, concurrency control and access method code tightly bound together in a storage engine for records. We propose a different approach,...

Dagstuhl Seminar Organizer Authors (2009)

Cliff Jones, David Lomet, Er Romanovsky, Gerhard Weikum, Alan Fekete, Marie-claude Gaudel, ...

This paper is based on a five-day workshop on “Atomicity in System Design and Execution ” that took place in Schloss Dagstuhl in Germany [5] in April 2004 and was attended by 32 people from...

Transaction Time Indexing with Version Compression (2009)

David Lomet, Mingsheng Hong

Immortal DB is a transaction time database system designed to enable high performance for temporal applications. It is built into a commercial database engine, Microsoft SQL Server. This paper...

Using the Lock Manager to Choose Timestamps (2009)

David Lomet

Our goal is to support transaction-time functionality that enables the coexistence of ordinary, non-temporal tables with transaction-time tables. In such a system, each transaction updating a...

Panelists. PANEL THE EFFECT OF LARGE MAIN MEMORY ON DATABASE SYSTEMS (2008)

Hector Garcia-molma, Dieter Gawlick Amdahl, David Lomet, Dina Bitton

The avallablhty of mexpenslve, large mam memories coupled with the demand for faster response time are brmgmg a new perspective to database technology Designers of database systems are reconsld-ermg...

ABSTRACT (2008)

David Lomet, Roger Barga, Redmond Wa, Rui Wang

Immortal DB builds transaction time database support into the SQL Server engine, not in middleware. Transaction time databases retain and provide access to prior states of a database. An update...

Dagstuhl Seminar Organizer Authors (2008)

Cliff Jones, David Lomet, Er Romanovsky, Gerhard Weikum, Alan Fekete, Marie-claude Gaudel, ...

This paper is based on a five-day workshop on “Atomicity in System Design and Execution ” that took place in Schloss Dagstuhl in Germany [5] in April 2004 and was attended by 32 people from...

ABSTRACT A Theory of Redo Recovery (2008)

David Lomet

Our goal is to understand redo recovery. We define an installation graph of operations in an execution, an ordering significantly weaker than conflict ordering from concurrency control. The...

Microsoft Corporation One Microsoft (2008)

David Lomet

Abstract: This paper defines a framework for explaining redo recovery after a system crash. In this framework, an installation graph explains the order in which operations must be installed into the...

Dagstuhl Seminar (Organizer Authors) (2008)

Cliff Jones, David Lomet, Alexander Romanovsky, Gerhard Weikum, Alan Fekete, Marie-claude Gaudel, ...

Abstract: This paper is a manifesto for future research on “atomicity ” in its many guises and is based on a five-day workshop on “Atomicity in System Design and Execution ” that took place...

Microsoft (2008)

David Lomet

Abstract: This paper defines a framework for explaining redo recovery after a system crash. In this framework, an installation graph explains the order in which operations must be installed into the...

Dagstuhl Seminar Organizer Authors (2008)

Cliff Jones, David Lomet, Er Romanovsky, Gerhard Weikum, Alan Fekete, Marie-claude Gaudel, ...

This paper is based on a five-day workshop on “Atomicity in System Design and Execution ” that took place in Schloss Dagstuhl in Germany [5] in April 2004 and was attended by 32 people from...

Dagstuhl Seminar Organizer Authors (2008)

Cliff Jones, David Lomet, Er Romanovsky, Gerhard Weikum, Alan Fekete, Marie-claude Gaudel, ...

This paper is based on a five-day workshop on "Atomicity in Sys-tem Design and Execution " that took place in Schloss Dagstuhl in Germany [5] in April 2004 and was attended by 32...

Overview (2008)

David Lomet, Mark Tuttle

Recovery can be extended to new domains at reduced logging cost by exploiting "logical " log operations. During recovery, a logical log operation may read data values from any...

Abstract Access Method Concurrency with Recovery (2008)

David Lomet, Betty Salzberg

Providing high concurrency in B+-trees has been studied extensively. But few efforts have been doc-umented for combining concurrency methods with a recovery scheme that preserves well-formed trees...

Dagstuhl Seminar Organizer Authors (2008)

Cliff Jones, David Lomet, Er Romanovsky, Gerhard Weikum, Alan Fekete, Marie-claude Gaudel, ...

This paper is based on a five-day ~orlishop on "At,omicity in System Design and Execution " that t,oolt place in Schloss Dagstuhl in Germany (5) in April 2004 alicl was attended by...

Using the Lock Manager to Choose Timestamps (2008)

David Lomet

Our goal is to support transaction-time functionality that enables the coexistence of ordinary, non-temporal tables with transaction-time tables. In such a system, each transaction updating a...

THEPERFORMANCEOFAMULTIVERSIONACCESS METHOD (2008)

David Lomet

The Tzme-Splrt B-tree IS an Integrated index struc-ture for a versroned trmestamped database It gradually migrates data from a current database to an hrstorrcal database, records mrgratmg when nodes...

Associate Editors (2007)

Letter Editor-in-chief, David Lomet, Vasanthakumar S. R, James P. Callan, W. Bruce Croft, David B. Lomet, ...

The Bulletin of the Technical Committee on Data Engineering is published quarterly and is distributed to all TC members. Its scope includes the design, implementation, modelling, theory and...

The BT-Forest: A Branched and Temporal Access Method (2007)

Betty Salzberg, David Lomet, Manuel Barrena, L. Jiang, Linan Jiang

We combine the ideas of time-varying data and branching versions to produce a new (paginated) access method, the BT-Forest. It is fully persistent in that it captures all the past states of a B +...

in the Subject line: On Digital's EASYnet: CRL::TECHREPORTS On the Internet: techreports@crl.dec.com (2007)

This Work, Georgios Evangelidis, Georgios Evangelidis, David Lomet, David Lomet, Betty Salzberg, ...

We describe a new access method, the hB P -tree, an adaptation of the Lomet and Salzberg hB-tree index to the constraints of their P-tree . The P-trees, a generalization of the B link -trees of...

Data Engineering (2007)

December Vol No, Letter Editor-in-chief, David Lomet, Letter Special, Christos Faloutsos, Peter J. Haas, ...

this paper we describe and evaluate several popular techniques for data reduction.

Data Engineering (2007)

December Vol, Letter Editor-in-chief, David Lomet, Rajeev Rastogi, Avi Silberschatz, Leana Golubchik, ...

A growing number of applications need access to video data stored in digital form on secondary storage devices (e.g., video-on-demand, multimedia messaging). As a result, video servers that are...

Data Engineering (2007)

December Vol, Letter Editor-in-chief, David Lomet, Rajeev Rastogi, Avi Silberschatz, Leana Golubchik, ...

A growing number of applications need access to video data stored in digital form on secondary storage devices (e.g., video-on-demand, multimedia messaging). As a result, video servers that are...

Data Engineering (2007)

December Vol, Letter Editor-in-chief, David Lomet, Michael A. Olson, Wei Michael Hong, Michael Ubell, ...

As network connectivity has continued its explosive growth and as storage devices have become smaller, faster, and less expensive, the number of online digitized images has increased rapidly....

Versioned Backups and Index Concurrency Results of Work-in-Progress (2007)

David Lomet, Betty Salzberg

We have been investigating two areas of interest in transaction processing: using a temporal index for backing up a database and breaking up index node structure changes into

1 Overview 1.1 History The Microsoft Database Research Group (2007)

David Lomet, Roger Barga, Surajit Chaudhuri, Paul Larson, Vivek Narasayya

Microsoft’s strategic interest in the database field dates from 1993 and the efforts of David Vaskevitch, who is now the Microsoft Vice President in charge of the database and transaction...

Symbol Binding and Resolution in Programming (2007)

Languages David Lomet, David Lomet

We propose a new explanation for the "binding" process in programming languages. Current explanations [6] rely on a run-time search of an environment that consists of # ############ #...

Transaction Time Support Inside a Database Engine (2006)

David Lomet, Roger Barga, Rui Wang

Transaction time databases retain and provide access to prior states of a database. An update “inserts ” a new record while preserving the old version. Immortal DB builds transaction time...

Recovery from Bad User Transactions (2006)

David Lomet

User written transaction code is responsible for the “C ” in ACID transactions, i.e., taking the database from one consistent state to the next. However, user transactions can be flawed and lead...

06121 Executive Summary -- Atomicity: A Unifying Concept in Computer Science (2006)

Weikum, Gerhard, Jones, Clifford B., Lomet, David, Romanovsky, Alexander

This seminar was based on and continued the interaction of different computer-science communities that was begun in an earlier Dagstuhl seminar in April 2004. Both seminars have aimed at a deeper...

06121 Abstracts Collection -- Atomicity: A Unifying Concept in Computer Science (2006)

Weikum, Gerhard, Jones, Clifford B., Lomet, David, Romanovsky, Alexander

From 19.03.06 to 24.03.06, the Dagstuhl Seminar 06121 ``Atomicity: A Unifying Concept in Computer Science'' was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl....

Immortal DB: Transaction Time Support for SQL Server (2005)

Lomet, David, Barga, Roger, Mokbel, Mohamed, Shegalov, German, Wang, Rui, Zhu, Yunyue, ...

Our {\em Immortal DB} prototype provides transaction time database support built into the Sql Server database engine, not layered on top. Transaction-time databases retain and provide access to all...

The Atomic Manifesto: a Story in Four Quarks (2005)

Jones, Cliff, Lomet, David, Romanovsky, Alexander, Weikum, Gerhard, Fekete, Alan, Gaudel, Marie-Claude, ...

This paper is based on a five-day workshop on "Atomicity in System Design and Execution" that took place in Schloss Dagstuhl in Germany in April 2004 and was attended by 32 people from different...

The Atomic Manifesto: a Story in Four Quarks (2005)

Jones, Cliff, Lomet, David, Romanovsky, Alexander, Weikum, Gerhard, Fekete, Alan, Gaudel, Marie-Claude, ...

This paper is based on a five-day workshop on "Atomicity in System Design and Execution" that took place in Schloss Dagstuhl in Germany [5] in April 2004 and was attended by 32 people from different...

Improving Logging and Recovery Performance in Phoenix/APP (2004)

Roger Barga, Shimin Chen, David Lomet

Phoenix/App supports software components whose states are made persistent across a system crash via redo recovery, replaying logged interactions. Our initial prototype force logged all request/reply...

The Atomic Manifesto: a Story in Four Quarks (2004)

Jones, Cliff, Lomet, David, Romanovsky, Alexander, Weikum, Gerhard, Fekete, Alan, Gaudel, Marie-Claude, ...

This report summarizes the viewpoints and insights gathered in the Dagstuhl Seminar on Atomicity in System Design and Execution, which was attended by 32 people from four different scientific...

Recovery Guarantees for Internet Applications (2004)

Barga, Roger, Lomet, David, Shegalov, German, Weikum, Gerhard

Internet-based e-services require application developers to deal explicitly with failures of the underlying software components, e.g. web servers, servlets, browser sessions, etc. This complicates...

EOS: Exactly-Once E-Service middleware (2002)

German Shegalov, Gerhard Weikum, Roger Barga, David Lomet

Today's web-based E-services do not handle system failures well. One of the most prominent examples is unintentional purchase of multiple copies of the same item (e.g., a DVD) in an online...

Persistent Applications via Automatic Recovery (2002)

Roger Barga David, David Lomet, Stelios Paparizos, Haifeng Yu, Sirish Ch

Building highly available enterprise applications using web-oriented middleware is hard. Runtime implementations frequently do not address the problems of application state persistence and...

The BT-Tree: A Branched and Temporal Access Method (2000)

Linan Jiang, Betty Salzberg, David Lomet, Manuel Barrena

Temporal databases assume a single line of time evolution. In other words, they support timeevolving data. However there are applications which require the support of temporal data with branched time...

The BT-Tree: A Branched and Temporal Access Method (1999)

Linan Jiang, Betty Salzberg, David Lomet, Manuel Barrena

Temporal databases assume a single line of time evolution. In other words, they support timeevolving data. However there are applications which require the support of temporal data with branched time...

Logical Logging to Extend Recovery to New Domains (1999)

David Lomet, Mark Tuttle

Recovery can be extended to new domains at reduced logging cost by exploiting "logical" log operations. During recovery, a logical log operation may read data values from any recoverable...

Efficient Transparent Application Recovery In Client-Server Information Systems (1998)

David Lomet, Gerhard Weikum

Database systems recover persistent data, providing high database availability. However, database applications, typically residing on client or "middle-tier" application-server machines,...

Efficient Transparent Application Recovery In Client-Server Information Systems (1998)

David Lomet, Gerhard Weikum

Database systems recover persistent data, providing high database availability. However, database applications, typically residing on client or "middle-tier" application-server machines,...

-tree: A Multi-attribute Index Supporting Concurrency, Recovery and Node Consolidation (1997)

Corresponding Betty Salzberg, Georgios Evangelidis Giorgos, Georgios Evangelidis, David Lomet, David Lomet, Betty Salzberg, ...

We propose a new multi-attribute index. Our approach combines the hB-tree, a multi-attribute index, and the \Pi-tree, an abstract index which offers efficient concurrency and recovery methods. We...

-Tree: A Multi-Attribute Index Supporting Concurrency, Recovery and Node Consolidation (1997)

Georgios Evangelidis, David Lomet, Betty Salzberg

.<F3.733e+05> We propose a new multi-attribute index. Our approach combines the hB-tree, a multi-attribute index, and the<F3.768e+05><F3.733e+05> #-tree, an abstract index which...

Replicated Indexes for Distributed Data (1996)

David Lomet

We describe a distributed index structure, in which data is distributed among multiple sites and indexes to the data are replicated over multiple sites. This permits good scalability as storage and...

Redo Recovery after System Crashes (1995)

David Lomet, Mark Tuttle

: This paper defines a framework for explaining redo recovery after a system crash. In this framework, an installation graph explains the order in which operations must be installed into the stable...

-tree: A Concurrent and Recoverable Multi-attribute Access Method (1994)

Georgios Evangelidis College, Georgios Evangelidis, David Lomet, Betty Salzberg

We describe a new access method, the hB \Pi -tree, an adaptation of an hB-tree index [LS90] to the constraints of a \Pi-tree [LS92]. \Pi-trees, a generalization of B link -trees [LY81], provide very...

IEEE Computer Society Bulletin of the Technical Committee on Data Engineering (Vol. 17 No. 4) (1994)

Guy Ferran, David Lomet, Shahram Ghandeharizadeh, Goetz Graefe, Meichun Hsu, Eliot Moss, ...

The SQL standardization community is hard at work adding object technology to the SQL relational database language. Are these experts merely engaged in a Quixotic waste of their organizations'...

Node Deletion in the . . . (1994)

Georgios Evangelidis, David Lomet, Betty Salzberg

The problem of node deletion in the hB \Pi -tree, a multi-attribute point data indexing method, is addressed. The hB \Pi -tree is a modified hB-tree [LS90] that provides concurrency and recovery and...

A Concurrent and Recoverable Multi-attribute Access Method 1 (1994)

Georgios Evangelidis, David Lomet, Betty Salzberg, Georgios Evangelidis, David Lomet, Betty Salzberg

The Cambridge laboratory became operational in 1988 and is located at One Kendall Square, near MIT. CRL engages in computing research to extend the state of the computing art in areas likely to be...

A New Presumed Commit Optimization for Two Phase Commit (1993)

Butler Lampson, David Lomet, Butler Lampson, David Lomet

The Cambridge laboratory became operational in 1988 and is located at One Kendall Square, near MIT. CRL engages in computing research to extend the state of the computing art in areas likely to be...

A New Presumed Commit Optimization for Two Phase Commit (1993)

Butler Lampson, David Lomet

Two phase commit (2PC) is used to coordinate the commitment of transactions in distributed systems. The standard 2PC optimization is the presumed abort variant, which uses fewer messages when...

A New Presumed Commit Optimization for Two Phase Commit (1993)

Butler Lampson, David Lomet

Two phase commit (2PC) is used to coordinate the commitment of transactions in distributed systems. The standard 2PC optimization is the presumed abort variant, which uses fewer messages when...

Key Range Locking Strategies for Improved Concurrency (1993)

David Lomet, David Lomet

"Phantoms" are records inserted into a concurrently selected set of records specified by a predicate such that the selection does not see a transaction consistent result. The usual locking...

A New Presumed Commit Optimization for Two Phase Commit (1993)

Butler Lampson, David Lomet

Two phase commit (2PC) is used for coordinating the commitment of transactions in distributed systems. The preferred 2PC optimization is the presumed abort variant, which reduces the number of...

Bulletin of the Technical Committee on Data Engineering (June, 1993 Vol. 16 No. 2) (1993)

Important Membership, March Issue, Rakesh Agrawal, David Lomet, ...

In many real world applications (even in banking), imprecise data is a matter of fact. However, classic database management systems provide little if any help in the management of imprecise data. We...

Key range locking strategies for improved concurrency (1993)

David Lomet, David Lomet

The Cambridge laboratory became operational in 1988 and is located at One Kendall Square, near MIT. CRL engages in computing research to extend the state of the computing art in areas likely to be...

Exploiting a history database for backup (1993)

David Lomet

Database systems provide media recovery by talc-ing periodic backups and applying a recovery log to a backup to r’estore the failed media. A transaction-time database is one that retains multiple...

ªA New Presumed Commit Optimization for Two Phase Commit,º (1993)

Butler Lampson, David Lomet

Two phase commit (ZPC) ia used to coordinate the commitment of trunsactiom in distributed systems. The standard 2PC optimization is the presumed abort variant, which wea fewer messages when...

Rollback Databases (1992)

David Lomet, David Lomet, Betty Salzberg, Betty Salzberg

Rollback databases are multiversion databases that use transaction time to identify the versions of the data. Such databases support queries that request information "as-of" some specific...

How the Rdb/VMS Data Sharing System Became Fast (1992)

T. K. Rengarajan, Peter Spiro, David Lomet, David Lomet, Rick Anderson, Rick Anderson

Recent versions of Rdb/VMS have shown dramatic performance increases compared with earlier versions. Performance enhancements have culminated in an 80% improvement between Rdb/VMS V3.0 and Rdb/VMS...

Private Lock Management (1992)

David Lomet, David Lomet

For a data sharing database system, substantial coordination cost is incurred to cope with the global (distributed) locking needed by these systems. Lock covering is a way to permit component systems...

Private Lock Management (1992)

David Lomet, David Lomet

The Cambridge laboratory became operational in 1988 and is located at One Kendall Square, near MIT. CRL engages in computing research to extend the state of the computing art in areas likely to be...

Concurrency and Recovery for Index Trees (1991)

David Lomet, David Lomet, Betty Salzberg, Betty Salzberg

Providing high concurrency in B + -trees has been studied extensively. But few efforts have been documented for combining concurrency methods with a recovery scheme that preserves well-formed trees...

MLR: A Recovery Method for Multi-level Systems (1991)

David Lomet, David B. Lomet

To achieve high concurrency in a database system has meant building a system that copes well with important special cases. Recent work on multilevel systems suggests a systematic way of providing...

Concurrency and Recovery for Index Trees (1991)

David Lomet, Betty Salzberg

.<F3.733e+05> Although many suggestions have been made for concurrency in B<F3.733e+05> +<F3.733e+05> -trees, few of these have considered recovery as well. We describe an approach...

Media Recovery with Time-Split (1991)

David Lomet, Betty Salzberg, David Lomet, Betty Salzberg

The Cambridge laboratory became operational in 1988 and is located at One Kendall Square, near MIT. CRL engages in computing research to extend the state of the computing art in areas likely to be...

Concurrency and Recovery for Index Trees (1991)

David Lomet, David Lomet, Betty Salzberg, Betty Salzberg

The Cambridge laboratory became operational in 1988 and is located at One Kendall Square, near MIT. CRL engages in computing research to extend the state of the computing art in areas likely to be...

Consistent Timestamping for Transactions in Distributed Systems (1990)

David Lomet

Tagging data in a database with timestamps that indicate when data was entered can be very useful. It permits a user to query the database as of some historical time. Further, it permits a user to...

The performance of a multiversion access method (1990)

David Lomet, Betty Salzberg

The Time-Split B-tree is an integrated index structure for a versioned timestamped database. It gradually migrates data from a current database to an historical database, records migrating when nodes...

The hB-tree: A multiattribute indexing method with good guaranteed performance (1990)

David Lomet, Betty Salzberg

A new multiattribute index structure called the hB-tree is introduced. It is derived from the K-D-B-tree of Robinson [15] but has additional desirable properties. The hB-tree internode search and...

Branched and Temporal Index Structures

Betty Salzberg, David Lomet

this paper, we combine the ideas of time-varying data and branching versions to produce and compare two new indexing structures: the BT (Branched and Temporal) Forest and the PBT-Tree (the Persistent...

Media Recovery with Time-Split B-trees

David Lomet, Betty Salzberg

Modern database systems provide media recovery by taking periodic backups and applying a transaction log to the backup to bring the data up-to-date. A multi-versioned database is one that retains and...

Recovery Guarantees for Internet Applications

Roger Barga David, David Lomet, German Shegalov, Gerhard Weikum

Internet-based e-services require application developers to deal explicitly with failures of the underlying software components, e.g. web servers, servlets, browser sessions, etc. This complicates...