Indian Institute of Technology Bombay

Indian Institute of Technology Hyderabad

Karthik Ramachandra

Sundararajarao Sudarshan

Arun Chaitanya Miriappalli

Varun Simhadri

Ravindra Guravannavar

Systems, methods, and computer-readable medium, are disclosed for transforming user-defined-function invocations in a query-based environment. A user-defined-function (UDF) and a query invoking the UDF are received. The UDF is parsed into a plurality of statements. A first expression tree corresponding to the UDF and a second expression tree corresponding the query are constructed, and merged using an operator to generate a transformed expression. The transformed expression is simplified, using transformation rules, if it is determined that is can be simplified.

Decorrelation of user-defined function invocations in queries

The present disclosure proposes the method for optimizing the performance of data base/web-service backed applications by automatically prefetching query results. The proposed system and methods automatically insert prefetch instructions at the earliest possible points across procedure calls in application source code, in presence of conditional branching and loops. A data flow analysis technique called anticipable expressions analysis is extended, to analyze anticipability of queries. The benefit of prefetching is limited due to the presence of assignment statements and conditional branches that precede the query execution statement. Enhancements such as code motion, chaining and rewriting prefetch requests are devised to increase benefits of prefetching. These techniques perform equivalence preserving program and query transformations.

Growing community of inventors

Maharashtra, India

Karthik Ramachandra