Abstract:  Cardinality estimates are a primary input to query optimizers to determine an appropriate join order. The seminal AMS sketch can estimate the cardinality of an equi-join between two relations using little space. Since then, two important advancements are the Count sketch, a method which significantly improves upon the sketching time, and secondly, an extension […]

Abstract The inception of Bitcoin and blockchain has renewed the vision of a democratic and decentralized computational paradigm, that is, to ingrain integrity, transparency, and accountability into the very fabric of the computational model. These fundamental concepts and the technologies behind them--a generic ledger-based data model, cryptographically ensured data integrity and transparent and accountable consensus-based […]