Name resolution of SQL objects

Informix^® uses the following form to identify an SQL object:

database[@dbservername]:][{owner|"owner"}.]identifier

The ANSI convention is to use double quotes for identifier delimiters (For example: "tabname"."colname").

When using double-quoted identifiers, both Informix and ORACLE become case sensitive. Unlike Informix, ORACLE database object names are stored in UPPERCASE in system catalogs. That means that SELECT "col1" FROM "tab1" will produce an error because those objects are identified by "COL1" and "TAB1" in ORACLE system catalogs.

in Informix ANSI compliant databases:

• The table name must include "owner", unless the connected user is the owner of the database object.
• The database server shifts the owner name to uppercase letters before the statement executes, unless the owner name is enclosed in double quotes.

With ORACLE, an object name takes the following form:

[(schema|"schema").](identifier|"identifier")[@database-link]

ORACLE has separate namespaces for different classes of objects (tables, views, triggers, indexes, clusters).

Object names are limited to 30 chars in ORACLE.

An ORACLE database schema is owned by a user (usually, the application administrator) and this user must create PUBLIC SYNONYMS to provide a global scope for his table names. PUBLIC SYNONYMS can have the same name as the schema objects they point to.