Efficient Processing of Relational Queries with Sum Constraints
نویسندگان
چکیده
Meal Example Consider a database storing nutritional information for single servings of different kinds of food in the following 4 relations: Meats, Vegetables, Fruits, and Beverages. All four relations have the same schema: name, cal, Vb6, Vc, fat, chol. Suppose that a meal consists of single servings of each of the four kinds of food. We are interested in finding meals that satisfy various nutritional requirements, such as restrictions on the number of calories, grams of saturated fat, and amount of Vitamin C. For example, the daily USDA recommendations for a 30-year old female, who is moderately active, are 1800-2200 calories, less than 18g of saturated fat and 300mg of cholesterol, and at least 4mg of Vitamin B6 and 76mg of Vitamin C. Assuming that a main meal carries about half of the daily nutritional values, we can find all such meals with the following SQL query:
منابع مشابه
On Estimators for Aggregate Relational Algebra Queries
CASE-DB is a relational database management system that allows users to specify time constraints in queries. For an aggregate query AGG(E) where AGG is one of COUNT, SUM and AVERAGE, and E is a relational algebra expression, CASE-DB uses statistical estimators to approximate the query. This paper extends our earlier work on statistical estimators of CASE-DB with the following features: (a) New ...
متن کاملRelational Databases Query Optimization using Hybrid Evolutionary Algorithm
Optimizing the database queries is one of hard research problems. Exhaustive search techniques like dynamic programming is suitable for queries with a few relations, but by increasing the number of relations in query, much use of memory and processing is needed, and the use of these methods is not suitable, so we have to use random and evolutionary methods. The use of evolutionary methods, beca...
متن کاملOptimization of Preference Queries under Hard Sum Constraints
Many important applications, e.g. planning tasks, demand the flexible and efficient use of personalization and preference handling techniques. Applying preference-based search technology could improve things quite a lot, e.g. using Preference SQLwhere preferences (i.e. soft constraints) can be combined with hard constraints. However, there are still fundamental efficiency issues that need to be...
متن کاملThe MD-join: An Operator for Complex OLAP
OLAP queries (i.e. group-by or cube-by queries with aggregation) have proven to be valuable for data analysis and exploration. Many decision support applications need very complex OLAP queries, requiring a fine degree of control over both the group definition and the aggregates that are computed. For example, suppose that the user has access to a data cube whose measure attribute is Sum(Sales)....
متن کاملConsistent Query Answers on Numerical Databases Under Aggregate Constraints
The problem of extracting consistent information from relational databases violating integrity constraints on numerical data is addressed. In particular, aggregate constraints defined as linear inequalities on aggregate-sum queries on input data are considered. The notion of repair as consistent set of updates at attributevalue level is exploited, and the characterization of several complexity ...
متن کاملApply Uncertainty in Document-Oriented Database (MongoDB) Using F-XML
As moving to big data world where data is increasing in unstructured way with high velocity, there is a need of data-store to store this bundle amount of data. Traditionally, relational databases are used which are now not compatible to handle this large amount of data, so it is needed to move on to non-relational data-stores. In the current study, we have proposed an extension of the Mongo...
متن کامل