Joined: 06 Jan 2004 Posts: 247 Location: Hyderabad
Collection is a set of packages.
Package is the executable access path code for the sql statements in the DBRM
Plan contains package list which is nothing but pointers to packages.
Here i give you some more information which clearly says you the use of plan,package and collection.
We can BIND the instructions for the SQL that was in the DBRM into a PLAN (the old way), or We can BIND the instructions into a PACKAGE (this also become old now).But binding the instructions into a plan works fine as long as the program will be standalone pgm.It has many drawbacks.After that we started binding instructions into a package
If only one DBRM could be bound into a PACKAGE, and if PGMA need to CALL PGMB and PGMB need to CALL PGMC etc etc., then a structure was needed to gather all of the PACKAGEs into a searchable list. This structure became a packagelist, rather than a memberlist, bound into a PLAN.
To solve a few more problems, IBM introduced the concept of COLLECTIONs. A collection is simply a way of grouping packages into meaningful groups. you could use COLLECTIONs to separate programs for different application areas, such as payroll and inventory.
Hence program bound into the COLLECTION will be accessible by the named PLAN.