Storage Model

N-ary Storage Model (Row/Record)

NonStop SQL uses the N-ary Storage Model, which is appropriate for heavy OLTP workloads.

Query Compilation

Code Generation

The query compiler transforms the SQL source commands into executable query plans in host language. The executable query plans and the SQL source commands are stored in a newly created object program file.

Views

Virtual Views

Whenever a view is created, NonStop SQL stores a view definition instead of the materialized table. Whenever a user selects data from a view, the data is directly retrieved from the underlying base tables.

Storage Architecture

Disk-oriented

The data of every table is stored in one or more disk files. Each disk file has a label storing the name and catalog information of the associated table.

Query Execution

Tuple-at-a-Time Model

Data Model

Relational

NonStop SQL supports the basic features of relational database management systems. What distinguish it from many other relational DBMS are the additional features providing excellent OLTP performance, availability, and scalability.

Indexes

B+Tree

NonStop SQL supports B+ tree index. By default, the primary key is used as the index of a table. To speed up the non-primary key look up, an index table can be created based on selected columns.