Abstract Effective query optimization is a core feature of any database management system. While most techniques make use simple metadata, such as cardinalities and other basic statistics, are based on more advanced metadata including data dependencies, functional, uniqueness, order, or inclusion dependencies. This survey provides an overview, intuitive descriptions, classifications execution s...

We present the second public data release of Dark Energy Survey, DES DR2, based on optical/near-infrared imaging by Camera mounted 4 m Blanco telescope at Cerro Tololo Inter-American Observatory in Chile. DR2 consists reduced single-epoch and coadded images, a source catalog derived from associated products assembled 6 yr science operations. This includes wide-area survey covering ?5000 deg2 so...

The Food Surveys Research Group (FSRG) is responsible for methods of data collection and processing of dietary intake data, including the What We Eat in America Survey, which is the dietary interview component of the National Health and Nutrition Examination Survey (NHANES). Many measures have been implemented to ensure accuracy of the dietary data, such as a state-of-theart data collection ins...

The assessment of data quality from different sources can be considered as a key challenge in supporting effective geospatial data integration and promoting collaboration in mapping projects. This paper presents a methodology for assessing positional and shape quality for authoritative large-scale data, such as Ordnance Survey (OS) UK data and General Directorate for Survey (GDS) Iraq data, and...