Como en todo lenguaje, existen ciertas palabras que están reservadas para usos específicos por lo que no se deberán utilizar para nombrar tablas o variables. Éstas son:
| ABSOLUTE | ACTION | ADD | ALLOCATE |
| ALTER | ARE | ASSERTION | AT |
| BETWEEN | BIT | BIT_LENGTH | BOTH |
| CASCADE | CASCADED | CASE | CAST |
| CATALOG | CHAR_LENGTH | CHARACTER_LENGTH | COALESCE |
| COLLATE | COLLATION | COLUMN | CONNECT |
| CONNECTION | CONSTRAINT | CONSTRAINTS | CONVERT |
| CORRESPONDING | CROSS | CURRENT_DATE | CURRENT_TIME |
| CURRENT_TIMESTAMP | CURRENT_USER | DATE | DAY |
| DEALLOCATE | DEFERRABLE | DEFERRED | DESCRIBE |
| DESCRIPTOR | DIAGNOSTICS | DISCONNECT | DOMAIN |
| DROP | ELSE | END-EXEC | EXCEPT |
| EXCEPTION | EXECUTE | EXTERNAL | EXTRACT |
| FALSE | FIRST | FULL | GET |
| GLOBAL | HOUR | IDENTITY | IMMEDIATE |
| INITIALLY | INNER | INPUT | INSENSITIVE |
| INTERSECT | INTERVAL | ISOLATION | JOIN |
| LAST | LEADING | LEFT | LEVEL |
| LOCAL | LOWER | MATCH | MINUTE |
| MONTH | NAMES | NATIONAL | NATURAL |
| NCHAR | NEXT | NO | NULLIF |
| OCTECT_LENGTH | ONLY | OUTER | OUTPUT |
| OVERLAPS | PAD | PARTIAL | POSITION |
| PREPARE | PRESERVE | PRIOR | READ |
| RELATIVE | RESTRICT | REVOKE | RIGHT |
| ROWS | SCROLL | SECOND | SESSION |
| SESSION_USER | SIZE | SPACE | SQLSTATE |
| SUBSTRING | SYSTEM_USER | TEMPORARY | THEN |
| TIME | TIMESTAMP | TMIEZONE_HOUR | TIMEZONE_MINUTE |
| TRAILING | TRANSACTION | TRANSLATE | TRANSLATION |
| TRIM | TRUE | UNKNOWN | UPPER |
| USAGE | USING | VALUE | VARCHAR |
| VARYING | WHEN | WRITE | YEAR |
| ZONE |