Introduction to NonStop SQL/MP

Why Use NonStop SQL/MP?

113425 Tandem Computers Incorporated 1–3

Solution

Reliability and transaction integrity. NonStop SQL/MP works with the NonStop Kernel

operating system and the NonStop Transaction Manager/MP (TM/MP) subsystem to

ensure that every piece of data exactly matches what was originally input and that a

transaction either completes or the database is returned to its state just before the

transaction started. If a disk drive fails, NonStop SQL/MP automatically uses the

mirrored copy of the disk drive, thus ensuring that no data is lost or misinterpreted

because of the hardware failure.

Availability. NonStop SQL/MP is designed so that it can be in use continuously. You

can perform all administration and database management functions while end users

are updating the database. (Some operations that change the structure of the database

can cause a very brief downtime for OLTP transactions.)

Scalability. You can easily increase the size of a NonStop SQL/MP database to

accommodate peak loads and the demands of a growing application. The same data

can be accessed by multiple processors, and no extra programming is required to

support the additional processors. Therefore, you can add processors and disk drives

to a system without having to change the application. Moreover, benchmarks have

shown over 99 percent scalability for systems that scale to more than 100 processors.

That is, when you add a processor, over 99 percent of that processor’s power is

available to your application.

Fast response. NonStop SQL/MP is tuned for OLTP performance. NonStop SQL

Release 1.0 was the first relational database to provide acceptable OLTP performance.

Since then, enhancements in parallel processing techniques and operations such as

joining tables and sorting data continue to improve response time.

Concurrency. NonStop SQL/MP can lock data at the individual row level. A lock

ensures that while one user updates data, no other users can access or update it. Thus,

many users can access the same table with minimal contention, because each user is

likely to access a different record. In addition, NonStop SQL/MP offers special locks

that allow users to read the data without affecting concurrent writes or updates. Most

OLTP applications also involve batch updates and reports. Through the mixed

workload feature of NonStop SQL/MP, batch jobs or long queries can be run at low

priority while the OLTP tasks are executing, without adversely affecting the response

time of the OLTP tasks.

Scenario: Decision

Support Systems (DSS)

Suppose your company operates a chain of retail stores. You are responsible for

ordering products to be sold in these stores. You must offer the products customers

want to buy and have the right amount of product on your shelves--enough to satisfy

demand, but not so much that you will have to sell outdated stock below your cost.

You have a separate system that manages your point-of-sale (POS) devices and tracks

each item sold in each store. Your stores sell over a million items a day.

Some items such as toothpaste turn over regularly. However, other items such as

Valentine’s Day gifts have dramatically different sales volumes in different stores and

different weeks leading up to the holiday. You monitor each day’s sales and place