cost-based query optimizer

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cost-based query optimizer

Software that optimizes an SQL query for the fastest processing, based on the size of the database files and other variables.
References in periodicals archive ?
The SQL Server query optimizer would first construct a query plan for a batch of T-SQL code, a stored procedure, or function, and then submit that plan for processing in a way that, once started, had to run to completion.
0 including improved query optimizer now supporting compound indexes, improved horizontal scale out with support of distributed databases, improved production environments due to new online database configuration capabilities, and general multi core performance improvements.
Sections cover foundations, identification of performance problems, the query optimizer, and optimization.
For example, we will describe the design of a query optimizer that compiles a query for execution and determines the best possible way among many alternative ways to execute a query.
Of course, query optimization is already one of the most complex and highly tuned components of a database system--it is not likely that the developers of existing systems will be willing or able to rewrite the query optimizer from scratch.
Therefore, queries with C functions in the qualification cannot be optimized by the POSTGRES query optimizer.
In addition, the INGRES query optimizer is acknowledged to be the best, and the company offers an excellent report generator.
The dramatic performance improvement is made possible by an algebraic query optimizer that is able to reuse work performed to answer prior queries.
First, SQL Server 2017 improves query performance in code containing multi-statement table valued functions by providing runtime cardinality estimates to the query optimizer, also known as "interleaved execution.
One central component of a query optimizer is its search strategy or enumeration algorithm.
Similarly, the modules User Interface, Application Interface, SQL Parser, and Distributed Query Optimizer are not used at the data location.
KeystoneML is analogous to the database query optimizer that is ubiquitous within relational database systems.