Virtual memory-mapped communication (VMMC) is a communication model providing direct data transfer between the sender's and receiver's virtual address spaces. This model eliminates operating system involvement in communication, provides full protection, supports user-level bu er management and zero-copy protocols, and minimizes software communication overhead. This paper describes system softwa...

Memory-mapped transactions combine the advantages of both memory mapping and transactions to provide a programming interface for concurrently accessing data on disk without explicit I/O or locking operations. This interface enables a programmer to design a complex serial program that accesses only main memory, and with little to no modification, convert the program into correct code with multip...

Shared Virtual Memory (SVM) provides a shared memory abstraction in systems that do not have a physically shared memory. Several architectures that provide this sharing abstraction without the scalability limitations of physical sharing have been proposed. However, there has not been much work in the area of database systems to exploit this scalable abstraction. In earlier work we proposed a sc...

Compressed text (self-)indexes have matured up to a point where they can replace a text by a data structure that requires less space and, in addition to giving access to arbitrary text passages, support indexed text searches. At this point those indexes are competitive with traditional text indexes (which are very large) for counting the number of occurrences of a pattern in the text. Yet, they...

Recently several database-based applications have emerged that are remote from data sources and need accurate histograms for query cardinality estimation. Traditional approaches for constructing histograms require complete access to data and are I/O and network intensive, and therefore no longer apply to these applications. Recent approaches use queries and their feedback to construct and maint...

in order to determine optimum landuses (in accordance with natural capability) and improve the current land management, landuse planning process was applied by using gis. within the framework of system analysis approach basic ecological and socio-economic , data were mapped. the mapped data were digitized and imported to idrisi and arc/info to build a database ,along with other descriptive data...

Relative fitness modeling is a new approach for predicting the performance and resource utilization of a workload when running on a particular storage device. In contrast with conventional device models, which expect deviceindependent workload characteristics as input, a relative fitness model makes predictions based on characteristics measured on a specific other device. As such, relative fitn...

O B J L O C / I N T S O R T S [/ OC O K O P S ; I N T > L O C N E X T ~ I/ )C > L O C V A R S i ~ I N T O K E Q N S ( N E X T ~ = I + I ) J B O I M ( A R R A Y = > S T O R E ) / L O C IT E M B O O L S O R T S ( A R R A y = > S T O R E ) { E L E M E N T = > I T E M ) { I N D E X = > L O C ) O P S ( N I L A R R A Y : -> A R R A Y = > N I L S T O R E ) M I I M ( P A I R = > S T A T E ) / S T O R E...

Despite continued innovations in design of I/O systems, I/O performance has not kept pace with the progress in processor and communication technology. This paper addresses this I/O problem from a compiler’s perspective, and presents an I/O optimization strategy based on access pattern and storage form (file layout) detection. The objective of our optimization strategy is to determine storage fo...