What happens when a query is executed in Oracle?

What happens when a query is executed?

Execution and Explain Plans These plans (the name is dependent on the database engine, but the terms are interchangeable) are generated after the query is parsed—they determine the set of operations required to retrieve the results of the query from memory or the storage subsytem.

What happens when you execute a SQL query?

Whenever SQL Server gets a query to execute it performs two major steps to return the query output. The first step is query compilation, which generates a query execution plan by the SQL Server relational engine and the second step is execution of the query execution plan by the SQL Server storage engine.

How the query is executed in Oracle database?

How an SQL query is executed in Oracle Database1An instance has started on a node where Oracle Database is installed, often called the host or database server.2A user starts an application spawning a user process. ... 3The server runs a listener that has the appropriate Oracle Net Services handler.

What is execute in Oracle?

The EXECUTE IMMEDIATE statement executes a dynamic SQL statement or anonymous PL/SQL block. You can use it to issue SQL statements that cannot be represented directly in PL/SQL, or to build up statements where you do not know all the table names, WHERE clauses, and so on in advance.