Technology Questions

An application behaves differently when running in foreground than in background because of the limitation of resources on iOS devices.

The simplest DB2 index is the B-tree and the B-tree's top page is called the root page. The root page entries represent the upper range limits of the index and are referenced first in a search. 

main() method is called by the JVM even before the instantiation of the class, hence it is declared as static.

When an object is passed by value, this means that a copy of the object is passed. Thus, even if changes are made to that object, it doesn’t affect the original value. 

When an object is passed by reference, this means that the actual object is not passed, rather a reference of the object is passed. Thus, any changes made by the external method, are also reflected in all places.

There are some differences:

COBOL II supports structured programming by using in line Performs and explicit scope terminators. It introduces new features (EVALUATE, SET. TO TRUE, CALL BY CONTEXT, etc). It permits programs to be loaded and addressed above the 16-megabyte line .  It does not support many old features (READY TRACE, REPORT-WRITER, ISAM, etc.). It offers enhanced CICS support.

GROUP BY partitions the selected rows on the distinct values of the column on which you group by. HAVING selects GROUPs which match the criteria specified