Stack unwinding is a process of calling all destructors for all automatic objects constructed at run time when an exception is thrown. Destructors are called between the places where the exception was thrown and where it is caught.

STL stands for Standard Template Library. It is a library of container templates approved by the ANSI committee for inclusion in the standard C++ specification.

A Stack is a linear structure in which insertions and deletions are always made at one end i.e the top - this is termed as last in, first out (LIFO). Stacks are useful when we need to check some syntex errors like missing parentheses. 

i.) Const - This variable means that if the memory is initialised once, it should not be altered by a program. 

ii.) Volatile - This variable means that the value in the memory location can be altered even though nothing in the program code modifies the contents. 

iii.) Mutable - This variable means that a particular member of a structure or class can be altered even if a particular structure variable, class, or class member function is constant.

- 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. 

The backup strategies that are provided by Oracle are as follows:

- Logical backup using Exports and import.

- Physical file system backup

- RMAN Recovery Manger which is also known as incremental files system backup.

We use SQLPASSTHROUGH options when we need applications to access data both in the front-end and back-end data servers with a single connection. SQL statements that cannot be executed in the solidDB front-end server are passed over to the back end. 

SQLPASSTHROUGH mode can be set as per session or per transaction. The connection between the front end and back end is made with a back-end compatible ODBC driver which is loaded dynamically in solidDB server.

Oracle HTTP Server is managed by OPMN which stands for Oracle Process Manager and Notification Server. With the use of opmnctl utility we can start, stop and restart Oracle HTTP Server. If we don’t use this utility the configuration management infrastructure cannot detect or communicate with the Oracle HTTP Server processes, and problems may occur.

The startproc command for the case of Windows is: ORACLE_HOME\opmn\bin> opmnctl [verbose] startproc ias-component=HTTP_Server.

To stop Oracle HTTP Server, use the stopproc command: Windows: ORACLE_HOME\opmn\bin> opmnctl [verbose] stopproc ias-component=HTTP_Server.