Which of the following is an accurate statement about packages?
A.
Packages provide a logical grouping of database objects.
B.
Packages contain control structures that are considered the bound form for SQL statements
C.
Packages describe the objects in a DB2 database and their relationship to each other
D.
Packages may be used during query optimization to improve the performance for a subset of
SELECT queries
Packages in DB2 are control-structure database objects that contain executable forms of SQL statements or placement holders for executable forms. In DB2 for Linux®, UNIX®, and Windows®, packages may also be referred to as access plans. Packages are stored in the database system catalog tables.
If an application intends to access a database using static SQL, the application developer must embed the appropriate SQL statements in the program source code. When the program source code is converted to an executable object (static SQL) or executed (dynamic SQL), the strategy for executing each embedded SQL statement is stored in a package as a single section. Each section is a bound form of the embedded SQL statement, and this form contains information such as which index to use and how to use the index (basically an access plan).
DB2 packages are used to execute SQL statements on the database server. They play a crucial role in how a DB2 client application interacts with the DB2 server.
The DB2 Runtime Client does not include any DB2 bind files. The task of binding is always left to administrators and best done during maintentance windows.
Embedded SQL packages: The second set includes packages that are created by the user in the form of embedded applications or stored procedures.
The following sections discuss the use of both kinds of packages in detail.
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