Explanation
The two steps that check out a database connection from the connection pool are DB Read and DB Write. The DB Read step executes a SQL query on a database and returns the result in a ResultSet variable. The DB Write step executes a SQL update, insert, or delete statement on a database and returns the number of rows affected. Both steps require a database connection to perform their operations. The database connection is checked out from the connection pool when the step is executed and checked back in when the step is completed1, pages 4-8 and 4-9. The following steps do not check out a database connection from the connection pool:
DB Get: This step retrieves a database connection from the connection pool and stores it in a DB Connection variable. The step does not execute any SQL statement on the database. The database connection remains checked out until it is explicitly released by the DB Release step1, page 4-7.
DB Release: This step releases a database connection that was previously checked out by the DB Get step. The step does not execute any SQL statement on the database. The database connection is returned to the connection pool and becomes available for other steps to use1, page
4-10. References: Cisco Unified Contact Center Express Editor Step Reference Guide, Release
11.6(2)