Technology Questions

The free subroutine frees a block of memory previously allocated by the malloc subroutine. Undefined results occur if the Pointer parameter is not a valid pointer. If the Pointer parameter is a null value, no action will occur. The realloc subroutine changes the size of the block of memory pointed to by the Pointer parameter to the number of bytes specified by the Size parameter and returns a new pointer to the block. The pointer specified by the Pointer parameter must have been created with the malloc, calloc, or realloc subroutines and not been deallocated with the free or realloc subroutines. Undefined results occur if the Pointer parameter is not a valid pointer.

- Clustering means one than one database server configured for the same user connection. When users connect, one of the server’s responds and connects based on availability. The user is completely ignorant of the fact that there are more than one database servers. It demands high cost due to infrastructure needs. Clustering is hence done on server level.

- Mirroring means, one has many configured databases on the same server. Mirrors are basically copies of the original database. Mirroring is hence done on database level. 

A reference variable provides an alias to a previously defined variable.

Data type & reference-name = variable name

ActiveX DLL:

It is an in process server. It runs within the application time.

ActiveX Exe:

It is an out of process server. MS-Excel is an activex exe.

when u call the excel from the vb application u can in the task manager an excel exe will run, whereas for dll u can't see like that.

SQL Server can be linked to any server provided it has OLE-DB provider from Microsoft to allow a link. E.g. Oracle has an OLE-DB provider for oracle that Microsoft provides to add it as linked server to SQL Server group.

INTRA PARTITION TD QUEUE : It is a goup of sequential records which are produced by the same and / or different transaction within a CICS region. These Qs are stored in only one physical file (VSAM) in a CICS region, which is prepared by the system programmer. Once a record is read from a queue, the record will be logically removed from the queue.

EXTRA PARTITION TD QUEUE:  It is a group of sequential record which interface between the transaction s of the CICS region and the systems outside of CICS region. Each of there TDQs is a separate physical file, and it may be on the disk, tap, printer or plotter.

Stack is a collection of objects that works in LIFO (Last in First out) mechanism while Queue is FIFO (First in First out). This means that the object that is inserted first is removed last in a stack while an object that is inserted first is removed first in a queue.