Query plan

Execution planaccess planexecutionexecution pathexecution plansplanningquery execution planQuery processing
A query plan (or query execution plan) is an ordered set of steps used to access data in a SQL relational database management system.wikipedia
26 Related Articles

Relational model

relationalrelational data modelrelationships
This is a specific case of the relational model concept of access plans.
The access plans and other implementation and operation details are handled by the DBMS engine, and are not reflected in the logical model.

Query optimization

query optimizeroptimizationQuery processing
When a query is submitted to the database, the query optimizer evaluates some of the different, correct possible plans for executing the query and returns what it considers the best option. In some databases the query plan can be reviewed, problems found, and then the query optimizer gives hints on how to improve it.
The query optimizer attempts to determine the most efficient way to execute a given query by considering the possible query plans.

Microsoft SQL Server

SQL ServerMS SQLMS SQL Server
The sequence of actions necessary to execute a query is called a query plan.

Hint (SQL)

hintshint
In some databases the query plan can be reviewed, problems found, and then the query optimizer gives hints on how to improve it.

SQL

Structured Query LanguageSQL databaseSQL Databases
A query plan (or query execution plan) is an ordered set of steps used to access data in a SQL relational database management system. Since SQL is declarative, there are typically many alternative ways to execute a given query, with widely varying performance.

Relational database

relational database management systemRDBMSrelational databases
A query plan (or query execution plan) is an ordered set of steps used to access data in a SQL relational database management system.

Declarative programming

declarativedeclarative languagedeclarative programming language
Since SQL is declarative, there are typically many alternative ways to execute a given query, with widely varying performance.

Information retrieval

queryretrievalqueries
When a query is submitted to the database, the query optimizer evaluates some of the different, correct possible plans for executing the query and returns what it considers the best option.

Database index

indexindexesindexing
Reviewing the query plan can present opportunities for new indexes or changes to existing indexes.

Select (SQL)

SELECTSQL query keyword
The database translates the query into a "query plan" which may vary between executions, database versions and database software.

CUBRID

Join (SQL)

joinjoinsInner join
Thus the result of the execution of the query above will be:

SQL syntax

Case (SQL)statementstwo flavours of conditional expressions
Queries allow the user to describe desired data, leaving the database management system (DBMS) to carry out planning, optimizing, and performing the physical operations necessary to produce that result as it chooses.

OpenCog

OpenCog Foundation
The rules are exactly the graph queries of the graph query subsystem, and so the rule engine vaguely resembles a query planner.

Cardinality (SQL statements)

cardinality
SQL databases use cardinality to help determine the optimal query plan for a given query.

Database tuning

tuning
Memory is allocated for data, execution plans, procedure cache, and.

Pervasive PSQL

Pervasive.SQL or PSQLrelational database engine