Informix Guide to SQL: Tutorial
Chapter 11: Granting and Limiting Access to Your Database
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In some databases, all data is accessible to every user. In others, this is not the case; some users are denied access to some or all of the data. You can restrict access to data at the following levels, which are the subject of this chapter:
When the database is stored in operating-system files, you can sometimes use the file-permission features of the operating system.
This level is not available when INFORMIX-Universal Server holds the database. It manages its own disk space, and the
operating-system rules do not apply.
You can use the
GRANT
and
REVOKE
statements to give or deny access to the database or to specific tables, and you can control the kinds of uses that people can make of the database.
You can use the
CREATE PROCEDURE
or
CREATE FUNCTION
statement to write and compile a stored routine, which controls and monitors the users who can read, modify, or create database tables. A
stored routine
is a stored function or a stored procedure. A
stored function
is an SPL routine that returns a value. A
stored procedure
is an SPL routine that does not return a value.
You can use the
CREATE VIEW
statement
to prepare a restricted or modified view of the data. The restriction can be vertical, which excludes certain columns, or horizontal, which excludes certain rows, or both.
You can combine
GRANT
and
CREATE VIEW
statements to achieve precise control over the parts of a table that a user can modify and with what data.
Informix Guide to SQL: Tutorial
, version 9.1
Copyright © 1998, Informix Software, Inc. All rights reserved.
