Getting Startedwith pureQuery

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Getting Started with pureQuery
D.4 The mechanics of static SQL with DB2
When an application executes static SQL statements in DB2, it needs an alternate way of
telling the server which statement it wants to execute. Since static SQL is already defined
at the server, the application does not need to send an SQL string to the server at runtime,
as it does for dynamic SQL. It only needs to identify to the server which pre-defined SQL
statement to execute. DB2 uses sections and packages as identifiers to organize and
manage the static SQL statements that have been defined. (higher level organizing units
such as collections, or for DB2 for z/OS plans or DBRMs are out of the scope of this
appendix.)
A package is the basic organizing unit for SQL statements at the server. A package is a
named and uniquely identifiable grouping of related SQL statements.
A section is the building block of a package. Each section is associated with one SQL
statement. A package usually has one or more sections identified by an integer number.
DB2 uses sections to execute both dynamic and static SQL.
Packages and sections are internally used by DB2 for execution of SQL statements in both
dynamic and static mode. While in static mode these organizing units are explicitly created
by the user at precompile and bind time, in dynamic mode they are used implicitly by DB2
when it binds the dynamic SQL statements. When connecting to DB2 from a Java
application, DB2 uses the implicit JDBC packages and sections to store the access plans
for the dynamically executed SQL statements. Because execution is dynamic, the SQL
string is provided by the application at runtime. The statement and its dynamically
determined access plan are depicted outside the package because the package does not
contain the definition of the statement or know the acces plan prior to execution time, as
illustrated in Figure D.6.