Introduction to NonStop SQL/MP

Additional Features
Introduction to NonStop SQL/MP
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First, NonStop SQL automatically issues a locking statement whenever you update,
insert, or delete data. The lock ensures that while you are updating the data, no one
else can access it or update it.
Second, NonStop SQL/MP locks individual records rather than a page of records,
allowing more users to access the database concurrently. Users only wait on a lock if
they want the particular record being locked. They do not have to wait if the record
they want is adjacent to a record that is locked.
Third, you can control the characteristics of locks. For example, you can specify
exclusive or shared access to data. You can also specify whether a lock will be released
after you finish accessing an individual record or held until you are finished with all
the records you are accessing.
Mixed Workload
Environment
Most applications perform a variety of tasks concurrently. Some tasks can require
immediate responses and others can be less critical. For example, the database activity
performed by an order entry clerk needs a high priority, whereas the database
retrievals needed to produce the nightly status report can execute at a lower priority.
Or, possibly, the CEO needs a report for a board meeting in 15 minutes, whereas an
end user might need a report by the next business day.
The data access manager (DP2), the system process that accesses the data on each disk
volume, contains a scheduling algorithm through which it can temporarily suspend
work on low-priority tasks in order to satisfy high-priority tasks.
Support for National
Languages
Increasingly, companies operate around the globe, and end users want to access data
in their own languages, whether it is English, French, German, or Japanese.
NonStop SQL/MP supports a variety of character sets so that data entered in the
major European and Asian languages can be represented in the database.
In addition, you can define your own collation sequence to determine the order in
which characters appear when you sort data. (The collation sequence differs in
different languages.) Moreover, different users can define and employ their own
collation sequences on the same system.
Active Data Dictionary The NonStop SQL/MP data dictionary contains descriptions of all the tables, views,
indexes, collations, and SQL object programs that make up the database. Whenever
you change any of these objects, NonStop SQL/MP immediately updates the data
dictionary so that all database operations use consistent definitions.
Also, if your tables are distributed on remote systems, NonStop SQL/MP ensures that
the data dictionaries on all systems have consistent definitions of the tables.
Even currently running programs can be flagged when you change any database
objects. NonStop SQL/MP can then recompile the invalid (flagged) programs and
produce new SQL execution plans if the current plans are inconsistent with the altered
environment.