This paper very briefly summarizes the features and technologies implemented in the IBM relationa... more This paper very briefly summarizes the features and technologies implemented in the IBM relational DBMS products. The topics covered include record and index management, concurrency control and recovery methods, commit protocols, query optimization and execution techniques, high availability and support for parallelism and distributed data. Some indications of likely future product directions are also given.
Proceedings of the 1992 ACM SIGMOD international conference on Management of data, 1992
{nwhan, pirahesh, kM&actWe present efficient and flexible methods which permit read-only tranaact... more {nwhan, pirahesh, kM&actWe present efficient and flexible methods which permit read-only tranaactiona that do not mind reading a possibly slightly old, but still consistent, version of the data base to execute without acquiring locks. This approach avoids the undesirable interferences between such queries and the typically shorter update transactions that cause unnecessary and costly delays. Indexed access by such queries ia also supported, unlike by the earlier methods. Old versions of records are maintained only in a transient fashion. Our methods are characterized by their flexibility (number of versions maintained and the timing of version switches, supporting partial rollbacks, and different recovery and buffering methods) and their efficiency (logging, garbage collection, version selection, and incremental, record-level versioning). Distributed data base environments are also supported, including commit protocols with the read-only optimization. We also describe efficient methods for garbage collecting unneeded older versiona.
Information Systems Development for Decentralized Organizations, 1995
In the past few years there has been an increasing interest in workflow applications as a way of ... more In the past few years there has been an increasing interest in workflow applications as a way of supporting complex business processes in modern corporations. Given the nature of the environment and the technology involved, workflow applications are inherently distributed and pose many interesting challenges to the system designer. In most cases, a client/server architecture is used in which knowledge about the processes being executed is centralized in one node to facilitate monitoring, auditing, and to simplify synchronization. In this paper, we explore a novel distributed architecture, Exotica/FMQM, for workflow systems in which the need for such a centralized database is eliminated. Instead, we use persistent messages as the means to store the information relevant to the execution of a business process. Our approach is to completely distribute the execution of a process so individual nodes are independent. The advantages of this approach are increased resilience to failures and greater scalability and flexibility of the system configuration.
Indian journal of otolaryngology and head and neck surgery : official publication of the Association of Otolaryngologists of India, 1997
The results of auditory brainstem evoked responses in 25 subjects of presbyacusis are compared wi... more The results of auditory brainstem evoked responses in 25 subjects of presbyacusis are compared with 25 age and sex matched controls. Absolute latent periods of wave I through V were significantly prolonged in presbyacusis group. Delayed wave I and no significant change in interwave interval latencies of I-V, III-V and mild shortening of interwave interval of I-III in presbyacusis is observed.
Indian journal of otolaryngology and head and neck surgery : official publication of the Association of Otolaryngologists of India, 2007
Cervical neuroblastoma is relatively uncommon. It present, most often as a firm mass in the later... more Cervical neuroblastoma is relatively uncommon. It present, most often as a firm mass in the lateral neck. Primary neuroblastomas of the neck usually arise in the cervical sympathetic ganglia. They are the sixth most common head and neck extracranial neoplasms. Neuroblastoma is the most common malignancy in children under 1 year of age. No known cause of Neuroblastoma has been reported.
This article presents an algorithm to refresh the contents of database snapshots. A database snap... more This article presents an algorithm to refresh the contents of database snapshots. A database snapshot is a read-only table whose contents are extracted from other tables in the database. The snapshot contents can be periodically refreshed to reflect the current state of the database. Snapshots are useful in many applications as a cost effective substitute for replicated data in a distributed database system. When the snapshot contents are a simple restriction and projection of a single base table, differential refresh techniques can reduce the message and update costs of the snapshot refresh operation. The algorithm presented annotates the base table to detect the changes which must be applied to the snapshot table during snapshot refresh. The cost of maintaining the base table annotations is minimal and the amount of data transmitted during snapshot refresh is close to optimal in most circumstances.
Indian Journal of Otolaryngology and Head & Neck Surgery, 1999
Audiovestibular functions in 50 cases of diabetes mellitus have been evaluated to find out the ty... more Audiovestibular functions in 50 cases of diabetes mellitus have been evaluated to find out the type of hearing loss. Diabetes mellitus causes a significant bilateral symmetrical hearing loss at higher frequencies and with the progress of disease and added complications the hearing further deteriorates..On control of diabetes hearing changes are found to be irreversible. However vestibular functions remain uninvolved in cases of diabetes rnellitus. A direct correlation was found between hearing loss and increasing blood sugar level.
In this one-page summary, I introduce the database aspects of Lotus Domino/Notes. These database ... more In this one-page summary, I introduce the database aspects of Lotus Domino/Notes. These database features are covered in detail in the corresponding SIGMOD99 tutorial available at www.almaden.ibm.com/u/mohan/domino_sigmod99.ps.
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2011
The problems of equilibrium structures and periods of oscillations of rotationally and/or tidally... more The problems of equilibrium structures and periods of oscillations of rotationally and/or tidally distorted polytropic models of stars in binary systems have been studied previously. In the studies, only the effects of gravitational and centrifugal forces while obtaining the Roche equipotential of such stars were considered. The Coriolis force were not considered. In the present study, we have included the effects of the Coriolis force also. The objective of this study is to investigate as to how the inclusion of the Coriolis force in the Roche equipotential affects the equilibrium structures and periods of oscillations of rotationally and/or tidally distorted stars. The results of our study show that the Coriolis force has no appreciable effect on the equilibrium structures and periods of small oscillations of polytropic models of stars in binary systems. The present study also confirms the earlier conclusions that uniform rotation decreases the eigenfrequencies of various modes of...
Workflow Management Systems (WFMSs) automate the execution of business processes in environments ... more Workflow Management Systems (WFMSs) automate the execution of business processes in environments encompassing large numbers of users distributed over a wide geographic area and using heterogeneous resources. Current implementations allow the definition and controlled execution of complex and long lived business processes as the basis for an enterprise-wide collaborative system but, in most cases, the autonomy of the users is greatly restricted due to architectural and design considerations. In particular, existing systems are built around a centralized server. As a result, users need to maintain an uninterrupted connection with the server to perform the different tasks assigned to them. This is a severe restriction, especially when considering the emergence of mobile computing, and the increase in use of laptops and small computers which are connected to the network only occasionally and which will, undoubtedly, be the tool of choice for many users. This paper addresses the problem of supporting disconnected workflow clients in large workflow management systems while still preserving the correctness of the overall execution and allowing coordinated interactions between the different users regardless of their location.
In this paper, I describe first the background behind the development of the original ARIES recov... more In this paper, I describe first the background behind the development of the original ARIES recovery method, and its significant impact on the commercial world and the research community. Next, I provide a brief introduction to the various concurrency control and recovery methods in the ARIES family of algorithms. Subsequently, I discuss some of the recent developments affecting the transaction management area and what these mean for the future. In ARIES, the concept of repeating history turned out to be an important paradigm. As I examine where transaction management is headed in the world of the internet, I observe history repeating itself in the sense of requirements that used to be considered significant in the mainframe world (e.g., performance, availability and reliability) now becoming important requirements of the broader information technology community as well.
whose keen interest in the field gave wings to my imagination and made me challenge my own limits... more whose keen interest in the field gave wings to my imagination and made me challenge my own limits. I am forever in gratitude for his meticulous guidance, understanding spirit , constant encouragement and inspiration, support all through the pursuance of this work , without which the completion of this project would not have been possible. I also place on record my deep appreciation and indebtedness to Dr.O.P.Pandey , for strongly supporting my vision and granting me the permission to work with Dr. A. K. Lal in the branch of Astrophysics. I would like to express my deep gratitude to Dr. Manoj K Sharma for his immense cooperation and efforts for permitting me to work with Dr. A .K. Lal. I also take this opportunity to express my sincere thanks to all the faculty members and the staff of School of Mathematics, Thapar University, whose names may all not be enumerated. Their contributions are sincerely appreciated and gratefully acknowledged. I owe my work to my parents for being my pillars of strength. It is because of their love, continuous support and blessings that I have gathered the courage to manifest my vision. I owe my undying determination to my mother, who has always been a great mentor to my soul. Above all, I express my earnest gratitude towards the Great Almighty, the author of knowledge and wisdom, for His infinite grace and love. CONTENTS CHAPTER DESCRIPTION PAGE No. CHAPTER ONE 1 1.1 Astrophysical Significance of Determining the Equilibrium Structure of 2 Rotationally, Tidally and Magnetically Distorted Binary Stars 1.2 Literature Review 4 1.3 Elementary Equations Determining the Equilibrium Structure of a Star 6 1.4 Averaging Technique of Kippenhahn and Thomas 10 1.5 Improved Expression for Roche Equipotentials Including the 15 Effect of Magnetic Forces 1.6 Proposed Work 24 CHAPTER TWO 25 2.1 Binary Stars 26 2.2 Effect of Magnetic Fields on the Mass Reduction and Transmission 28 2.3 Generations of Poloidal and Toroidal Magnetic Fields 28 2.4 Magnetic Braking 29 2.5 Equilibrium Structures of Rotationally, Tidally and 31 Magnetically Distorted Non-Synchronous Binary Model of Stars 2.6 Computation of Surface Area, Volume and other Physical Parameters 33 of Rotationally, Tidally and Magnetically Distorted Polytropic Model of Stars 2.7 Equilibrium Structures of Rotationally, Tidally and Magnetically Distorted 34 Polytropic Models of Stars CHAPTER THREE 3.1 Numerical Computations 3.2 Conclusion and Discussion of Results 3.3 Scope for Future Work
Proceedings of the National Academy of Sciences, 2000
We previously produced three congenic strains carrying lupus susceptibility genes (Sle1-Sle3) fro... more We previously produced three congenic strains carrying lupus susceptibility genes (Sle1-Sle3) from the lupus-prone NZM2410 mouse on the C57BL/6 background and characterized their component phenotypes.Sle1mediates the loss of tolerance to nuclear antigens;Sle2lowers the activation threshold of B cells; andSle3mediates a dysregulation of CD4+T cells. We have now created a collection of bi- and tricongenic strains with these intervals and assessed the autoimmune phenotypes they elicit in various combinations. Our results indicate thatSle1is key for the development of fatal lupus. The combination ofSle1withSle2,Sle3, or the BXSB-derived autoimmune accelerating geneyaaresults in the development of systemic autoimmunity with variably penetrant severe glomerulonephritis culminating in kidney failure. In contrast, two locus combinations ofSle2,Sle3, andyaafailed to mediate fatal disease. These results indicate that the loss of tolerance to chromatin mediated bySle1is essential for disease p...
Association of Intra-Abdominal Pathologies and Vascular Anomalies with Infrarenal Aortic Aneurysm: A Computed Tomographic Study
Cardiovascular Surgery
The prevalence of potentially significant intra-abdominal pathologies or vascular anomalies in ca... more The prevalence of potentially significant intra-abdominal pathologies or vascular anomalies in candidates for infrarenal aortic aneurysm repair remains unclear. This study retrospectively reviewed 130 consecutive patients with aortic aneurysms (4.5–10.0 cm in largest diameter) who had undergone contrast-enhanced abdominal computed tomography. The overall incidence of potentially significant pathologies was 31.5%. Gallstones were detected in 25 patients (19.2%). adrenal masses in six (4.6%), pancreatic tumors in two (1.5%), renal stones in two (1.5%), liver metastases in one (0.8%), retroperitoneal lymphoma in one (0.8%) and left gastric artery aneurysm in one (0.8%). Other pathologies included renal cysts in 42 patients (32.3%), colonic diverticulosis in nine (6.9%) and hepatic cysts in three (2.3%). Major vascular anomalies were encountered in only three of the 130 patients (2.3%) and these included two with a left-sided inferior vena cava and one case of retroaortic left renal vei...
Algorithms for the management of remote backup data bases for disaster recovery
Proceedings of IEEE 9th International Conference on Data Engineering
... Figure 1: ARIES Recovery Scenario - Log Records of a Single Transaction ... So, on a take-ove... more ... Figure 1: ARIES Recovery Scenario - Log Records of a Single Transaction ... So, on a take-over, the undos of incomplete transactions will be per-formed by processing the stable storage version of the log in reverse chronological order, as in ARIES and other recovery methods. ...
R* is an experimental prototype distributed database management system. The computation needed to... more R* is an experimental prototype distributed database management system. The computation needed to perform a sequence of multisite user transactions in R* is structured as a tree of processes communicating over virtual circuit communication links. Distributed computation can be supported by providing a server process per site which performs requests on behalf of remote users. Alternatively, a new process could be created to service each incoming request. Instead of using a shared server process or using the process per request approach, R* creates a process associated with the computation of the user on the first request to the remote site. This process is incorporated into the tree of processes serving a single user and is retained for the duration of the user computation. This approach allows R* to factor some of the request execution overhead into the process creation phase, and simplifies the retention of user and transaction context at the multiple sites of the distributed compu...
Proceedings of the 2003 ACM SIGMOD international conference on Management of data, 2003
ABSTRACT The education industry has a very poor record of productivity gains. In this brief artic... more ABSTRACT The education industry has a very poor record of productivity gains. In this brief article, I outline some of the ways the teaching of a college course in database systems could be made more efficient, and staff time used more productively. These ideas ...
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