Description: A global temporary table is a type of data structure in SQL databases that allows for temporary storage of information accessible from multiple sessions. Unlike local temporary tables, which are visible only to the session that created them, global temporary tables can be used by any session with access to the database. This makes them a valuable tool for sharing temporary data among different users or processes. Global temporary tables are created using the appropriate SQL statement and, once defined, can be used to store intermediate results of queries, perform complex calculations, or manage data that does not need to be persistent. Their use is common in situations where quick and efficient access to temporary data is required, facilitating the optimization of SQL queries by reducing the need for repeated calculations or redundant data access. In summary, global temporary tables are an effective solution for managing temporary data in database environments, enhancing efficiency and collaboration among different user sessions.
Uses: Global temporary tables are primarily used in scenarios where temporary data needs to be shared among multiple user sessions. They are useful in ETL (Extract, Transform, Load) processes, where intermediate data needs to be stored before being processed or loaded into permanent tables. They are also employed in applications that require complex calculations or data analysis that do not need to be persistent, allowing developers and analysts to work more efficiently.
Examples: A practical example of a global temporary table is its use in a reporting system where multiple users need access to a set of intermediate data to generate reports. For instance, an analyst might create a global temporary table to store results from a complex query, and then other users can access that table for further analysis without needing to repeat the original query. Another case is in applications where user data during a session can be temporarily stored for use by different user sessions.
