Description: The ‘Query Execution Cost’ refers to an estimate of the resources required to execute a query in a database. This cost can include various factors such as CPU time, memory used, disk access, and network usage, among others. In the context of databases, each SQL query can have a different cost depending on its complexity, the amount of data involved, and the database structure. SQL query optimization aims to reduce this cost, thereby improving the overall performance of the system. Techniques such as index creation, query rewriting, and the selection of more efficient execution plans are employed to achieve this. Understanding execution cost is crucial for developers and database administrators as it allows them to identify performance bottlenecks and make informed decisions on enhancing query efficiency. Additionally, many modern databases provide tools and metrics to analyze execution cost, facilitating the identification of improvement areas and the implementation of optimization strategies.
