SYNONYMS 
The system table DOMAIN.SYNONYMS contains all the synonyms for which the current user has privileges.
Structure
OWNER |
CHAR(32) |
Name of the owner of the synonym |
SYNONYMNAME |
CHAR(32) |
Name of the synonym |
PUBLIC |
CHAR(3) |
Synonym is PUBLIC (YES | NO) |
TABLESCHEMANAME |
CHAR(32) |
Name of the schema of the table |
TABLEOWNER |
CHAR(32) |
Name of the owner of the table |
TABLENAME |
CHAR(32) |
Name of the table |
CREATEDATE |
DATE |
Creation date of the synonym |
CREATETIME |
TIME |
Creation time of the synonym |
COMMENT |
CLOB |
Comment on the synonym |
More Information
Evaluating System Tables, SYNONYMS
SQL Reference Manual, Synonym Name (synonym_name)