Query execution plan
Understanding query execution plans is an essential aspect of query optimization. It refers to the steps that the database takes to retrieve the data from the database and return the results to the user. Understanding these steps is critical in identifying bottlenecks and inefficiencies in the query, which can then be addressed to improve the performance of the query:
- What is a query execution plan? A query execution plan is a detailed map of the steps that the database takes to execute a SQL query. It shows the order in which the database accesses the data, the methods used to retrieve the data, and the resources required to run the query.
- How can we view a query execution plan? Query execution plans can be viewed using tools provided by the database management system, such as the EXPLAIN PLAN in Oracle or the SHOWPLAN in SQL Server. These tools provide a graphical representation of the query execution plan, making it easier to understand and analyze...