NON STOP SQL

The NonStop SQL/MP relational database management system combines the standard features of a relational database with additional features that provide data integrity,high availability, high performance, and excellent scalability. NonStop SQL/MP is specifically designed for large data processing environments that maintain a variety of applications performing critical business tasks.

RDBS

  • Relational Data Base Management System.

  • Used for storage and retrieval of data.

  • Data can be treated as 2-dimensional tables “Relations”.

  • Data can be combined from multiple tables.

  • Complex data access can be achieved using only a single command.

SQLCI

  • NonStop SQL/MP Conversational Interface Command.

  • SQLCI [/ [IN <in-file>] [, OUT <list-file>] , [, NOWAIT] [, <run-option>] …/][<sqlci-command> ;

  • SQLCI commands (e.g. INVOKE, LOAD, SHOW, etc.) are issued in an SQLCI session.

Catalogs

  • Set of tables and indexes that describe SQL objects.

  • Change of security of the catalog can affect users of objects described in the catalog.

JOIN

A Join is an operation that combines two tables or views to form a new table. A Join query is a query that requests columns from more than one table or view

  • Inner Join – Discards rows do not satisfy the predicates

  • Outer Join – Returns all rows

VIEWS

A view is a logical table created with a CREATE VIEW statement. A view has a file label but has no actual data. A view name must be a Guardian name Protection view. Derived from a single table. Short hand view. Derived from 1 or more tables or other views

CURSORS

CURSOR is a named mechanism defined by a SELECT statement. Operations for each CURSOR are

  • DECLARE defines the CURSOR

  • OPEN determines the result table

  • FETCH fills the CURSOR

  • DELETE or UPDATE WHERE CURRENT deletes or updates at the current position of the cursor

  • CLOSE releases the result table

EMBEDDED SQL

Application programming interface for SQL Consists of a set of SQL statements and declarations included in C, COBOL85, Pascal or TAL programs.

  • Static SQL – Coded directly into the program and compiled prior to the execution

  • Dynamic SQL – Statement built and compiled during program execution

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