Karthik Ramachandra

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— Synchronous execution of queries or Web service requests forces the calling application to block until the query/request is satisfied. The performance of applications can be significantly improved by asynchronous submission of queries, which allows the application to perform other processing instead of blocking while the query is executed, and to(More)
In this paper we address the problem of optimizing performance of database/web-service backed applications by means of automatically prefetching query results. Prefetching has been performed in earlier work based on predicting query access patterns; however such prediction is often of limited value, and can perform unnecessary prefetches. There has been(More)
— We present DBridge, a novel static analysis and program transformation tool to optimize database access. Traditionally , rewrite of queries and programs are done independently, by the database query optimzier and the language compiler respectively , leaving out many optimization opportunities. Our tool aims to bridge this gap by performing holistic(More)
We describe DBridge, a novel program analysis and transformation tool to optimize database and web service access. Traditionally, rewrite of queries and programs are done independently, by the database query optimizer and the language compiler respectively, leaving out many optimization opportunities. Our tool aims to bridge this gap by performing holistic(More)
—The performance of database/Web-service backed applications can be significantly improved by asynchronous submission of queries/requests well ahead of the point where the results are needed, so that results are likely to have been fetched already when they are actually needed. However, manually writing applications to exploit asynchronous query submission(More)
—Queries containing user-defined functions (UDFs) are widely used, since they allow queries to be written using a mix of imperative language constructs and SQL, thereby increasing the expressive power of SQL; further, they encourage modularity, and make queries easier to understand. However, not much attention has been paid to their optimization, except for(More)
Recent years have seen growing interest in bringing together independently developed techniques in the areas of optimizing compilers and relational query optimization, to improve performance of database applications. These approaches cut across the boundaries of general purpose programming languages and SQL, thereby exploiting many optimization(More)
Optimizing the performance of database applications is an area of practical importance, and has received significant attention in recent years. In this paper we present an approach to this problem which is based on extracting a concise algebraic representation of (parts of) an application, which may include imperative code as well as SQL queries. The(More)
To lower hosting costs and service prices, database-as-a-service (DBaaS) providers strive to maximize cluster utilization without negatively affecting their users' service experience. Some of the most effective approaches for increasing service efficiency result in the over-booking of the cluster with user databases. For instance, one approach is to reclaim(More)
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