db2 bind on luw

https://www.ibm.com/support/knowledgecenter/SSEPGG_10.5.0/com.ibm.db2.luw.apdv.embed.doc/doc/c0005563.html

Binding embedded SQL packages to a database

 

Binding is the process of creating a package from a bind file and storing it in a database.

Application, bind file, and package relationships

Database applications use packages for some of the same reasons that applications are compiled: improved performance and compactness. By precompiling an SQL statement, the statement is compiled into the package when the application is built, instead of at run time. Each statement is parsed, and a more efficiently interpreted operand string is stored in the package. At run time, the code generated by the precompiler calls run-time services database manager APIs with any variable information required for input or output data, and the information stored in the package is executed.

The advantages of precompilation apply only to static SQL statements. SQL statements that are executed dynamically (using PREPARE and EXECUTE or EXECUTE IMMEDIATE) are not precompiled; therefore, they must go through the entire set of processing steps at run time.

With the DB2® bind file description (db2bfd) utility, you can easily display the contents of a bind file to examine and verify the SQL statements within it. You can also display the precompile options used to create the bind file using the DB2 bind file description (db2bfd) utility. This can be useful in problem determination related to the bind file for your application.

You can set the STATICASDYNAMIC string on the GENERIC parameter of the BIND command to "yes" to instruct the DB2 database manager to store all statements in the catalogs and mark them as incremental bind. At run time, when the package is first loaded, the database manager uses the current session environment (rather than the package) to set up the section entries and other entities (text is populated and the package cache is accessed). Thereafter, the statements in the bound file behave the same as they would if you were using dynamic SQL. For example, sections will be implicitly recompiled for Database Definition Language invalidations, special register updates, and so on. The DB2 database manager provides this feature to facilitate the migration of embedded SQL C applications from other database systems.

 
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