Server User Manual

Non-cursor SQL statement
An SQL statement used for data manipulation, the non-cursor SQL statement does not use a cursor to specify rows to
be manipulated. Instead, the rows to be processed are specified in the search condition specified in the SQL
statement.
NOT NULL constraint
A constraint on a column of a table. This constraint prohibits rows in the table for which the value in the column is
NULL.
NULL
The value of the data in a specified column of a row in a table that is undefined.
Number of key values that differ
Optimization information that refers to the number of key values of storage data in a database that differ from one
another. For example, if all the storage data key values in a database are different, the number of different key values
matches the storage data count. Conversely, if all the storage data key values are the same, the number of different
key values is one.
OBJECT structure
A storage structure of SymfoWARE/RDB database base tables. This structure is applied to base tables for handling
image, voice, and other types of multimedia data.
Related terms:
SEQUENTIAL structure, RANDOM structure
Open Systems Interconnection/Remote Database Access (OSI/RDA)
OSI is an international standard for interconnecting different types of computers. This standard is being developed by
the International Organization for Standardization (ISO) and the International Telegraph and Telephone Consultative
Committee (CCITT). RDA is an OSI application layer standard for interoperation of databases between different types
of systems. RDA makes it possible to perform processes such as retrieval and update using the SQL database
language in databases on different types of systems.
Operating environment file
A file for defining the operating environment used when an application program is executed. Operating environment
files include client operating environment files and server operating environment files. A server operating environment
file is used for tuning the system-provided files for the application program.
Optimization
Determining the most efficient processing procedures for the search conditions by investigating tables bound to SQL
statement instructions.
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