C. SQL 關鍵字

Table C.1 列出了在 SQL 標準和 PostgreSQL 15.2 中作為關鍵字的所有標記。相關說明提供於第 4.1.1 節中。 （由於篇幅原因，僅收錄了 SQL 標準的最新兩個版本，以及用於歷史對比的 SQL-92，與其他中間標準版本差異較小。）

SQL 區分保留(reserved)關鍵字和非保留(non-reserved)關鍵字。 根據標準，只有保留關鍵字才是真正的關鍵字； 他們永遠不允許作為標識字串。 非保留關鍵字則只在特定的用法中有特殊的含義，而在其他用法中可以作為標識字串使用。 大多數非保留關鍵字實際上是 SQL 指定的內建資料表和函數的名稱。非保留關鍵字的概念本質上只是為了聲明在某些用法中增加了一些預先定義的含義。

在 PostgreSQL 解析器中，情況有點複雜。 有幾種不同類別的標記，從永遠不能用作標識字串的標記，到在解析器中絕對沒有特殊地位，但被視為普通標識字串的標記都有。 （後者通常是 SQL 指定的函數。）即使保留關鍵字在 PostgreSQL 中也沒有完全保留，而是可以用作欄位標籤（例如 SELECT 55 AS CHECK 是可以的，儘管 CHECK 是保留關鍵字） .

在 Table C.1 的 PostgreSQL 欄位中，我們將解析器明確知道但允許作為欄位名稱或資料表名稱的那些關鍵字分類為“non-reserved”。 一些非保留的關鍵字不能用作函數或資料型別名稱，並相應地進行標記。 （這些詞大多表示具有特殊語法的內建函數或資料型別。函數或型別仍然可用，但使用者不能重新定義。）標記為“reserved”的是那些不允許作為欄位或資料表名稱的標記。 允許一些保留關鍵字作為函數或資料型別的名稱； 這也顯示在表格中。 如果沒有這樣標記，保留關鍵字僅允許作為欄位標籤。 此欄中的空白項目表示該關鍵字被 PostgreSQL 視為普通標識字串。

此外，雖然大多數關鍵字可以直接用作欄位標籤而毋須在它們之前使用 AS（如第 7.3.2 節所述），但有一些關鍵詞需要前導 AS 以避免歧義。 在下表中這些關鍵字會標記為“requires AS”。

一般來說，如果使用任何列出的關鍵字作為標識字的命令出現解析錯誤的時候，您應該嘗試將標識字以雙引號括住，再查看問題是否消失。

在研究 Table C.1 之前，重要的是要了解，在 PostgreSQL 中沒有保留關鍵字並不意味著沒有實作與該關鍵字相關的功能。 同樣地，關鍵字的存在也不表示其功能的存在。

Table C.1. SQL Key Words

Key Word	PostgreSQL	SQL:2016	SQL:2011	SQL-92
A		non-reserved	non-reserved
ABORT	non-reserved
ABS		reserved	reserved
ABSENT		reserved	non-reserved
ABSOLUTE	non-reserved	non-reserved	non-reserved	reserved
ACCESS	non-reserved
ACCORDING		non-reserved	non-reserved
ACOS		reserved
ACTION	non-reserved	non-reserved	non-reserved	reserved
ADA		non-reserved	non-reserved	non-reserved
ADD	non-reserved	non-reserved	non-reserved	reserved
ADMIN	non-reserved	non-reserved	non-reserved
AFTER	non-reserved	non-reserved	non-reserved
AGGREGATE	non-reserved
ALL	reserved	reserved	reserved	reserved
ALLOCATE		reserved	reserved	reserved
ALSO	non-reserved
ALTER	non-reserved	reserved	reserved	reserved
ALWAYS	non-reserved	non-reserved	non-reserved
ANALYSE	reserved
ANALYZE	reserved
AND	reserved	reserved	reserved	reserved
ANY	reserved	reserved	reserved	reserved
ARE		reserved	reserved	reserved
ARRAY	reserved, requires AS	reserved	reserved
ARRAY_AGG		reserved	reserved
ARRAY_​MAX_​CARDINALITY		reserved	reserved
AS	reserved, requires AS	reserved	reserved	reserved
ASC	reserved	non-reserved	non-reserved	reserved
ASENSITIVE	non-reserved	reserved	reserved
ASIN		reserved
ASSERTION	non-reserved	non-reserved	non-reserved	reserved
ASSIGNMENT	non-reserved	non-reserved	non-reserved
ASYMMETRIC	reserved	reserved	reserved
AT	non-reserved	reserved	reserved	reserved
ATAN		reserved
ATOMIC	non-reserved	reserved	reserved
ATTACH	non-reserved
ATTRIBUTE	non-reserved	non-reserved	non-reserved
ATTRIBUTES		non-reserved	non-reserved
AUTHORIZATION	reserved (can be function or type)	reserved	reserved	reserved
AVG		reserved	reserved	reserved
BACKWARD	non-reserved
BASE64		non-reserved	non-reserved
BEFORE	non-reserved	non-reserved	non-reserved
BEGIN	non-reserved	reserved	reserved	reserved
BEGIN_FRAME		reserved	reserved
BEGIN_PARTITION		reserved	reserved
BERNOULLI		non-reserved	non-reserved
BETWEEN	non-reserved (cannot be function or type)	reserved	reserved	reserved
BIGINT	non-reserved (cannot be function or type)	reserved	reserved
BINARY	reserved (can be function or type)	reserved	reserved
BIT	non-reserved (cannot be function or type)			reserved
BIT_LENGTH				reserved
BLOB		reserved	reserved
BLOCKED		non-reserved	non-reserved
BOM		non-reserved	non-reserved
BOOLEAN	non-reserved (cannot be function or type)	reserved	reserved
BOTH	reserved	reserved	reserved	reserved
BREADTH	non-reserved	non-reserved	non-reserved
BY	non-reserved	reserved	reserved	reserved
C		non-reserved	non-reserved	non-reserved
CACHE	non-reserved
CALL	non-reserved	reserved	reserved
CALLED	non-reserved	reserved	reserved
CARDINALITY		reserved	reserved
CASCADE	non-reserved	non-reserved	non-reserved	reserved
CASCADED	non-reserved	reserved	reserved	reserved
CASE	reserved	reserved	reserved	reserved
CAST	reserved	reserved	reserved	reserved
CATALOG	non-reserved	non-reserved	non-reserved	reserved
CATALOG_NAME		non-reserved	non-reserved	non-reserved
CEIL		reserved	reserved
CEILING		reserved	reserved
CHAIN	non-reserved	non-reserved	non-reserved
CHAINING		non-reserved
CHAR	non-reserved (cannot be function or type), requires AS	reserved	reserved	reserved
CHARACTER	non-reserved (cannot be function or type), requires AS	reserved	reserved	reserved
CHARACTERISTICS	non-reserved	non-reserved	non-reserved
CHARACTERS		non-reserved	non-reserved
CHARACTER_LENGTH		reserved	reserved	reserved
CHARACTER_​SET_​CATALOG		non-reserved	non-reserved	non-reserved
CHARACTER_SET_NAME		non-reserved	non-reserved	non-reserved
CHARACTER_SET_SCHEMA		non-reserved	non-reserved	non-reserved
CHAR_LENGTH		reserved	reserved	reserved
CHECK	reserved	reserved	reserved	reserved
CHECKPOINT	non-reserved
CLASS	non-reserved
CLASSIFIER		reserved
CLASS_ORIGIN		non-reserved	non-reserved	non-reserved
CLOB		reserved	reserved
CLOSE	non-reserved	reserved	reserved	reserved
CLUSTER	non-reserved
COALESCE	non-reserved (cannot be function or type)	reserved	reserved	reserved
COBOL		non-reserved	non-reserved	non-reserved
COLLATE	reserved	reserved	reserved	reserved
COLLATION	reserved (can be function or type)	non-reserved	non-reserved	reserved
COLLATION_CATALOG		non-reserved	non-reserved	non-reserved
COLLATION_NAME		non-reserved	non-reserved	non-reserved
COLLATION_SCHEMA		non-reserved	non-reserved	non-reserved
COLLECT		reserved	reserved
COLUMN	reserved	reserved	reserved	reserved
COLUMNS	non-reserved	non-reserved	non-reserved
COLUMN_NAME		non-reserved	non-reserved	non-reserved
COMMAND_FUNCTION		non-reserved	non-reserved	non-reserved
COMMAND_​FUNCTION_​CODE		non-reserved	non-reserved
COMMENT	non-reserved
COMMENTS	non-reserved
COMMIT	non-reserved	reserved	reserved	reserved
COMMITTED	non-reserved	non-reserved	non-reserved	non-reserved
COMPRESSION	non-reserved
CONCURRENTLY	reserved (can be function or type)
CONDITION		reserved	reserved
CONDITIONAL		non-reserved
CONDITION_NUMBER		non-reserved	non-reserved	non-reserved
CONFIGURATION	non-reserved
CONFLICT	non-reserved
CONNECT		reserved	reserved	reserved
CONNECTION	non-reserved	non-reserved	non-reserved	reserved
CONNECTION_NAME		non-reserved	non-reserved	non-reserved
CONSTRAINT	reserved	reserved	reserved	reserved
CONSTRAINTS	non-reserved	non-reserved	non-reserved	reserved
CONSTRAINT_CATALOG		non-reserved	non-reserved	non-reserved
CONSTRAINT_NAME		non-reserved	non-reserved	non-reserved
CONSTRAINT_SCHEMA		non-reserved	non-reserved	non-reserved
CONSTRUCTOR		non-reserved	non-reserved
CONTAINS		reserved	reserved
CONTENT	non-reserved	non-reserved	non-reserved
CONTINUE	non-reserved	non-reserved	non-reserved	reserved
CONTROL		non-reserved	non-reserved
CONVERSION	non-reserved
CONVERT		reserved	reserved	reserved
COPY	non-reserved	reserved
CORR		reserved	reserved
CORRESPONDING		reserved	reserved	reserved
COS		reserved
COSH		reserved
COST	non-reserved
COUNT		reserved	reserved	reserved
COVAR_POP		reserved	reserved
COVAR_SAMP		reserved	reserved
CREATE	reserved, requires AS	reserved	reserved	reserved
CROSS	reserved (can be function or type)	reserved	reserved	reserved
CSV	non-reserved
CUBE	non-reserved	reserved	reserved
CUME_DIST		reserved	reserved
CURRENT	non-reserved	reserved	reserved	reserved
CURRENT_CATALOG	reserved	reserved	reserved
CURRENT_DATE	reserved	reserved	reserved	reserved
CURRENT_​DEFAULT_​TRANSFORM_​GROUP		reserved	reserved
CURRENT_PATH		reserved	reserved
CURRENT_ROLE	reserved	reserved	reserved
CURRENT_ROW		reserved	reserved
CURRENT_SCHEMA	reserved (can be function or type)	reserved	reserved
CURRENT_TIME	reserved	reserved	reserved	reserved
CURRENT_TIMESTAMP	reserved	reserved	reserved	reserved
CURRENT_​TRANSFORM_​GROUP_​FOR_​TYPE		reserved	reserved
CURRENT_USER	reserved	reserved	reserved	reserved
CURSOR	non-reserved	reserved	reserved	reserved
CURSOR_NAME		non-reserved	non-reserved	non-reserved
CYCLE	non-reserved	reserved	reserved
DATA	non-reserved	non-reserved	non-reserved	non-reserved
DATABASE	non-reserved
DATALINK		reserved	reserved
DATE		reserved	reserved	reserved
DATETIME_​INTERVAL_​CODE		non-reserved	non-reserved	non-reserved
DATETIME_​INTERVAL_​PRECISION		non-reserved	non-reserved	non-reserved
DAY	non-reserved, requires AS	reserved	reserved	reserved
DB		non-reserved	non-reserved
DEALLOCATE	non-reserved	reserved	reserved	reserved
DEC	non-reserved (cannot be function or type)	reserved	reserved	reserved
DECFLOAT		reserved
DECIMAL	non-reserved (cannot be function or type)	reserved	reserved	reserved
DECLARE	non-reserved	reserved	reserved	reserved
DEFAULT	reserved	reserved	reserved	reserved
DEFAULTS	non-reserved	non-reserved	non-reserved
DEFERRABLE	reserved	non-reserved	non-reserved	reserved
DEFERRED	non-reserved	non-reserved	non-reserved	reserved
DEFINE		reserved
DEFINED		non-reserved	non-reserved
DEFINER	non-reserved	non-reserved	non-reserved
DEGREE		non-reserved	non-reserved
DELETE	non-reserved	reserved	reserved	reserved
DELIMITER	non-reserved
DELIMITERS	non-reserved
DENSE_RANK		reserved	reserved
DEPENDS	non-reserved
DEPTH	non-reserved	non-reserved	non-reserved
DEREF		reserved	reserved
DERIVED		non-reserved	non-reserved
DESC	reserved	non-reserved	non-reserved	reserved
DESCRIBE		reserved	reserved	reserved
DESCRIPTOR		non-reserved	non-reserved	reserved
DETACH	non-reserved
DETERMINISTIC		reserved	reserved
DIAGNOSTICS		non-reserved	non-reserved	reserved
DICTIONARY	non-reserved
DISABLE	non-reserved
DISCARD	non-reserved
DISCONNECT		reserved	reserved	reserved
DISPATCH		non-reserved	non-reserved
DISTINCT	reserved	reserved	reserved	reserved
DLNEWCOPY		reserved	reserved
DLPREVIOUSCOPY		reserved	reserved
DLURLCOMPLETE		reserved	reserved
DLURLCOMPLETEONLY		reserved	reserved
DLURLCOMPLETEWRITE		reserved	reserved
DLURLPATH		reserved	reserved
DLURLPATHONLY		reserved	reserved
DLURLPATHWRITE		reserved	reserved
DLURLSCHEME		reserved	reserved
DLURLSERVER		reserved	reserved
DLVALUE		reserved	reserved
DO	reserved
DOCUMENT	non-reserved	non-reserved	non-reserved
DOMAIN	non-reserved	non-reserved	non-reserved	reserved
DOUBLE	non-reserved	reserved	reserved	reserved
DROP	non-reserved	reserved	reserved	reserved
DYNAMIC		reserved	reserved
DYNAMIC_FUNCTION		non-reserved	non-reserved	non-reserved
DYNAMIC_​FUNCTION_​CODE		non-reserved	non-reserved
EACH	non-reserved	reserved	reserved
ELEMENT		reserved	reserved
ELSE	reserved	reserved	reserved	reserved
EMPTY		reserved	non-reserved
ENABLE	non-reserved
ENCODING	non-reserved	non-reserved	non-reserved
ENCRYPTED	non-reserved
END	reserved	reserved	reserved	reserved
END-EXEC		reserved	reserved	reserved
END_FRAME		reserved	reserved
END_PARTITION		reserved	reserved
ENFORCED		non-reserved	non-reserved
ENUM	non-reserved
EQUALS		reserved	reserved
ERROR		non-reserved
ESCAPE	non-reserved	reserved	reserved	reserved
EVENT	non-reserved
EVERY		reserved	reserved
EXCEPT	reserved, requires AS	reserved	reserved	reserved
EXCEPTION				reserved
EXCLUDE	non-reserved	non-reserved	non-reserved
EXCLUDING	non-reserved	non-reserved	non-reserved
EXCLUSIVE	non-reserved
EXEC		reserved	reserved	reserved
EXECUTE	non-reserved	reserved	reserved	reserved
EXISTS	non-reserved (cannot be function or type)	reserved	reserved	reserved
EXP		reserved	reserved
EXPLAIN	non-reserved
EXPRESSION	non-reserved	non-reserved	non-reserved
EXTENSION	non-reserved
EXTERNAL	non-reserved	reserved	reserved	reserved
EXTRACT	non-reserved (cannot be function or type)	reserved	reserved	reserved
FALSE	reserved	reserved	reserved	reserved
FAMILY	non-reserved
FETCH	reserved, requires AS	reserved	reserved	reserved
FILE		non-reserved	non-reserved
FILTER	non-reserved, requires AS	reserved	reserved
FINAL		non-reserved	non-reserved
FINALIZE	non-reserved
FINISH		non-reserved
FIRST	non-reserved	non-reserved	non-reserved	reserved
FIRST_VALUE		reserved	reserved
FLAG		non-reserved	non-reserved
FLOAT	non-reserved (cannot be function or type)	reserved	reserved	reserved
FLOOR		reserved	reserved
FOLLOWING	non-reserved	non-reserved	non-reserved
FOR	reserved, requires AS	reserved	reserved	reserved
FORCE	non-reserved
FOREIGN	reserved	reserved	reserved	reserved
FORMAT		non-reserved
FORTRAN		non-reserved	non-reserved	non-reserved
FORWARD	non-reserved
FOUND		non-reserved	non-reserved	reserved
FRAME_ROW		reserved	reserved
FREE		reserved	reserved
FREEZE	reserved (can be function or type)
FROM	reserved, requires AS	reserved	reserved	reserved
FS		non-reserved	non-reserved
FULFILL		non-reserved
FULL	reserved (can be function or type)	reserved	reserved	reserved
FUNCTION	non-reserved	reserved	reserved
FUNCTIONS	non-reserved
FUSION		reserved	reserved
G		non-reserved	non-reserved
GENERAL		non-reserved	non-reserved
GENERATED	non-reserved	non-reserved	non-reserved
GET		reserved	reserved	reserved
GLOBAL	non-reserved	reserved	reserved	reserved
GO		non-reserved	non-reserved	reserved
GOTO		non-reserved	non-reserved	reserved
GRANT	reserved, requires AS	reserved	reserved	reserved
GRANTED	non-reserved	non-reserved	non-reserved
GREATEST	non-reserved (cannot be function or type)
GROUP	reserved, requires AS	reserved	reserved	reserved
GROUPING	non-reserved (cannot be function or type)	reserved	reserved
GROUPS	non-reserved	reserved	reserved
HANDLER	non-reserved
HAVING	reserved, requires AS	reserved	reserved	reserved
HEADER	non-reserved
HEX		non-reserved	non-reserved
HIERARCHY		non-reserved	non-reserved
HOLD	non-reserved	reserved	reserved
HOUR	non-reserved, requires AS	reserved	reserved	reserved
ID		non-reserved	non-reserved
IDENTITY	non-reserved	reserved	reserved	reserved
IF	non-reserved
IGNORE		non-reserved	non-reserved
ILIKE	reserved (can be function or type)
IMMEDIATE	non-reserved	non-reserved	non-reserved	reserved
IMMEDIATELY		non-reserved	non-reserved
IMMUTABLE	non-reserved
IMPLEMENTATION		non-reserved	non-reserved
IMPLICIT	non-reserved
IMPORT	non-reserved	reserved	reserved
IN	reserved	reserved	reserved	reserved
INCLUDE	non-reserved
INCLUDING	non-reserved	non-reserved	non-reserved
INCREMENT	non-reserved	non-reserved	non-reserved
INDENT		non-reserved	non-reserved
INDEX	non-reserved
INDEXES	non-reserved
INDICATOR		reserved	reserved	reserved
INHERIT	non-reserved
INHERITS	non-reserved
INITIAL		reserved
INITIALLY	reserved	non-reserved	non-reserved	reserved
INLINE	non-reserved
INNER	reserved (can be function or type)	reserved	reserved	reserved
INOUT	non-reserved (cannot be function or type)	reserved	reserved
INPUT	non-reserved	non-reserved	non-reserved	reserved
INSENSITIVE	non-reserved	reserved	reserved	reserved
INSERT	non-reserved	reserved	reserved	reserved
INSTANCE		non-reserved	non-reserved
INSTANTIABLE		non-reserved	non-reserved
INSTEAD	non-reserved	non-reserved	non-reserved
INT	non-reserved (cannot be function or type)	reserved	reserved	reserved
INTEGER	non-reserved (cannot be function or type)	reserved	reserved	reserved
INTEGRITY		non-reserved	non-reserved
INTERSECT	reserved, requires AS	reserved	reserved	reserved
INTERSECTION		reserved	reserved
INTERVAL	non-reserved (cannot be function or type)	reserved	reserved	reserved
INTO	reserved, requires AS	reserved	reserved	reserved
INVOKER	non-reserved	non-reserved	non-reserved
IS	reserved (can be function or type)	reserved	reserved	reserved
ISNULL	reserved (can be function or type), requires AS
ISOLATION	non-reserved	non-reserved	non-reserved	reserved
JOIN	reserved (can be function or type)	reserved	reserved	reserved
JSON_ARRAY		reserved
JSON_ARRAYAGG		reserved
JSON_EXISTS		reserved
JSON_OBJECT		reserved
JSON_OBJECTAGG		reserved
JSON_QUERY		reserved
JSON_TABLE		reserved
JSON_TABLE_PRIMITIVE		reserved
JSON_VALUE		reserved
K		non-reserved	non-reserved
KEEP		non-reserved
KEY	non-reserved	non-reserved	non-reserved	reserved
KEYS		non-reserved
KEY_MEMBER		non-reserved	non-reserved
KEY_TYPE		non-reserved	non-reserved
LABEL	non-reserved
LAG		reserved	reserved
LANGUAGE	non-reserved	reserved	reserved	reserved
LARGE	non-reserved	reserved	reserved
LAST	non-reserved	non-reserved	non-reserved	reserved
LAST_VALUE		reserved	reserved
LATERAL	reserved	reserved	reserved
LEAD		reserved	reserved
LEADING	reserved	reserved	reserved	reserved
LEAKPROOF	non-reserved
LEAST	non-reserved (cannot be function or type)
LEFT	reserved (can be function or type)	reserved	reserved	reserved
LENGTH		non-reserved	non-reserved	non-reserved
LEVEL	non-reserved	non-reserved	non-reserved	reserved
LIBRARY		non-reserved	non-reserved
LIKE	reserved (can be function or type)	reserved	reserved	reserved
LIKE_REGEX		reserved	reserved
LIMIT	reserved, requires AS	non-reserved	non-reserved
LINK		non-reserved	non-reserved
LISTAGG		reserved
LISTEN	non-reserved
LN		reserved	reserved
LOAD	non-reserved
LOCAL	non-reserved	reserved	reserved	reserved
LOCALTIME	reserved	reserved	reserved
LOCALTIMESTAMP	reserved	reserved	reserved
LOCATION	non-reserved	non-reserved	non-reserved
LOCATOR		non-reserved	non-reserved
LOCK	non-reserved
LOCKED	non-reserved
LOG		reserved
LOG10		reserved
LOGGED	non-reserved
LOWER		reserved	reserved	reserved
M		non-reserved	non-reserved
MAP		non-reserved	non-reserved
MAPPING	non-reserved	non-reserved	non-reserved
MATCH	non-reserved	reserved	reserved	reserved
MATCHED	non-reserved	non-reserved	non-reserved
MATCHES		reserved
MATCH_NUMBER		reserved
MATCH_RECOGNIZE		reserved
MATERIALIZED	non-reserved
MAX		reserved	reserved	reserved
MAXVALUE	non-reserved	non-reserved	non-reserved
MEASURES		reserved
MEMBER		reserved	reserved
MERGE	non-reserved	reserved	reserved
MESSAGE_LENGTH		non-reserved	non-reserved	non-reserved
MESSAGE_OCTET_LENGTH		non-reserved	non-reserved	non-reserved
MESSAGE_TEXT		non-reserved	non-reserved	non-reserved
METHOD	non-reserved	reserved	reserved
MIN		reserved	reserved	reserved
MINUTE	non-reserved, requires AS	reserved	reserved	reserved
MINVALUE	non-reserved	non-reserved	non-reserved
MOD		reserved	reserved
MODE	non-reserved
MODIFIES		reserved	reserved
MODULE		reserved	reserved	reserved
MONTH	non-reserved, requires AS	reserved	reserved	reserved
MORE		non-reserved	non-reserved	non-reserved
MOVE	non-reserved
MULTISET		reserved	reserved
MUMPS		non-reserved	non-reserved	non-reserved
NAME	non-reserved	non-reserved	non-reserved	non-reserved
NAMES	non-reserved	non-reserved	non-reserved	reserved
NAMESPACE		non-reserved	non-reserved
NATIONAL	non-reserved (cannot be function or type)	reserved	reserved	reserved
NATURAL	reserved (can be function or type)	reserved	reserved	reserved
NCHAR	non-reserved (cannot be function or type)	reserved	reserved	reserved
NCLOB		reserved	reserved
NESTED		non-reserved
NESTING		non-reserved	non-reserved
NEW	non-reserved	reserved	reserved
NEXT	non-reserved	non-reserved	non-reserved	reserved
NFC	non-reserved	non-reserved	non-reserved
NFD	non-reserved	non-reserved	non-reserved
NFKC	non-reserved	non-reserved	non-reserved
NFKD	non-reserved	non-reserved	non-reserved
NIL		non-reserved	non-reserved
NO	non-reserved	reserved	reserved	reserved
NONE	non-reserved (cannot be function or type)	reserved	reserved
NORMALIZE	non-reserved (cannot be function or type)	reserved	reserved
NORMALIZED	non-reserved	non-reserved	non-reserved
NOT	reserved	reserved	reserved	reserved
NOTHING	non-reserved
NOTIFY	non-reserved
NOTNULL	reserved (can be function or type), requires AS
NOWAIT	non-reserved
NTH_VALUE		reserved	reserved
NTILE		reserved	reserved
NULL	reserved	reserved	reserved	reserved
NULLABLE		non-reserved	non-reserved	non-reserved
NULLIF	non-reserved (cannot be function or type)	reserved	reserved	reserved
NULLS	non-reserved	non-reserved	non-reserved
NULL_ORDERING		non-reserved
NUMBER		non-reserved	non-reserved	non-reserved
NUMERIC	non-reserved (cannot be function or type)	reserved	reserved	reserved
OBJECT	non-reserved	non-reserved	non-reserved
OCCURRENCE		non-reserved
OCCURRENCES_REGEX		reserved	reserved
OCTETS		non-reserved	non-reserved
OCTET_LENGTH		reserved	reserved	reserved
OF	non-reserved	reserved	reserved	reserved
OFF	non-reserved	non-reserved	non-reserved
OFFSET	reserved, requires AS	reserved	reserved
OIDS	non-reserved
OLD	non-reserved	reserved	reserved
OMIT		reserved
ON	reserved, requires AS	reserved	reserved	reserved
ONE		reserved
ONLY	reserved	reserved	reserved	reserved
OPEN		reserved	reserved	reserved
OPERATOR	non-reserved
OPTION	non-reserved	non-reserved	non-reserved	reserved
OPTIONS	non-reserved	non-reserved	non-reserved
OR	reserved	reserved	reserved	reserved
ORDER	reserved, requires AS	reserved	reserved	reserved
ORDERING		non-reserved	non-reserved
ORDINALITY	non-reserved	non-reserved	non-reserved
OTHERS	non-reserved	non-reserved	non-reserved
OUT	non-reserved (cannot be function or type)	reserved	reserved
OUTER	reserved (can be function or type)	reserved	reserved	reserved
OUTPUT		non-reserved	non-reserved	reserved
OVER	non-reserved, requires AS	reserved	reserved
OVERFLOW		non-reserved
OVERLAPS	reserved (can be function or type), requires AS	reserved	reserved	reserved
OVERLAY	non-reserved (cannot be function or type)	reserved	reserved
OVERRIDING	non-reserved	non-reserved	non-reserved
OWNED	non-reserved
OWNER	non-reserved
P		non-reserved	non-reserved
PAD		non-reserved	non-reserved	reserved
PARALLEL	non-reserved
PARAMETER	non-reserved	reserved	reserved
PARAMETER_MODE		non-reserved	non-reserved
PARAMETER_NAME		non-reserved	non-reserved
PARAMETER_​ORDINAL_​POSITION		non-reserved	non-reserved
PARAMETER_​SPECIFIC_​CATALOG		non-reserved	non-reserved
PARAMETER_​SPECIFIC_​NAME		non-reserved	non-reserved
PARAMETER_​SPECIFIC_​SCHEMA		non-reserved	non-reserved
PARSER	non-reserved
PARTIAL	non-reserved	non-reserved	non-reserved	reserved
PARTITION	non-reserved	reserved	reserved
PASCAL		non-reserved	non-reserved	non-reserved
PASS		non-reserved
PASSING	non-reserved	non-reserved	non-reserved
PASSTHROUGH		non-reserved	non-reserved
PASSWORD	non-reserved
PAST		non-reserved
PATH		non-reserved	non-reserved
PATTERN		reserved
PER		reserved
PERCENT		reserved	reserved
PERCENTILE_CONT		reserved	reserved
PERCENTILE_DISC		reserved	reserved
PERCENT_RANK		reserved	reserved
PERIOD		reserved	reserved
PERMISSION		non-reserved	non-reserved
PERMUTE		reserved
PIPE		non-reserved
PLACING	reserved	non-reserved	non-reserved
PLAN		non-reserved
PLANS	non-reserved
PLI		non-reserved	non-reserved	non-reserved
POLICY	non-reserved
PORTION		reserved	reserved
POSITION	non-reserved (cannot be function or type)	reserved	reserved	reserved
POSITION_REGEX		reserved	reserved
POWER		reserved	reserved
PRECEDES		reserved	reserved
PRECEDING	non-reserved	non-reserved	non-reserved
PRECISION	non-reserved (cannot be function or type), requires AS	reserved	reserved	reserved
PREPARE	non-reserved	reserved	reserved	reserved
PREPARED	non-reserved
PRESERVE	non-reserved	non-reserved	non-reserved	reserved
PREV		non-reserved
PRIMARY	reserved	reserved	reserved	reserved
PRIOR	non-reserved	non-reserved	non-reserved	reserved
PRIVATE		non-reserved
PRIVILEGES	non-reserved	non-reserved	non-reserved	reserved
PROCEDURAL	non-reserved
PROCEDURE	non-reserved	reserved	reserved	reserved
PROCEDURES	non-reserved
PROGRAM	non-reserved
PRUNE		non-reserved
PTF		reserved
PUBLIC		non-reserved	non-reserved	reserved
PUBLICATION	non-reserved
QUOTE	non-reserved
QUOTES		non-reserved
RANGE	non-reserved	reserved	reserved
RANK		reserved	reserved
READ	non-reserved	non-reserved	non-reserved	reserved
READS		reserved	reserved
REAL	non-reserved (cannot be function or type)	reserved	reserved	reserved
REASSIGN	non-reserved
RECHECK	non-reserved
RECOVERY		non-reserved	non-reserved
RECURSIVE	non-reserved	reserved	reserved
REF	non-reserved	reserved	reserved
REFERENCES	reserved	reserved	reserved	reserved
REFERENCING	non-reserved	reserved	reserved
REFRESH	non-reserved
REGR_AVGX		reserved	reserved
REGR_AVGY		reserved	reserved
REGR_COUNT		reserved	reserved
REGR_INTERCEPT		reserved	reserved
REGR_R2		reserved	reserved
REGR_SLOPE		reserved	reserved
REGR_SXX		reserved	reserved
REGR_SXY		reserved	reserved
REGR_SYY		reserved	reserved
REINDEX	non-reserved
RELATIVE	non-reserved	non-reserved	non-reserved	reserved
RELEASE	non-reserved	reserved	reserved
RENAME	non-reserved
REPEATABLE	non-reserved	non-reserved	non-reserved	non-reserved
REPLACE	non-reserved
REPLICA	non-reserved
REQUIRING		non-reserved	non-reserved
RESET	non-reserved
RESPECT		non-reserved	non-reserved
RESTART	non-reserved	non-reserved	non-reserved
RESTORE		non-reserved	non-reserved
RESTRICT	non-reserved	non-reserved	non-reserved	reserved
RESULT		reserved	reserved
RETURN	non-reserved	reserved	reserved
RETURNED_CARDINALITY		non-reserved	non-reserved
RETURNED_LENGTH		non-reserved	non-reserved	non-reserved
RETURNED_​OCTET_​LENGTH		non-reserved	non-reserved	non-reserved
RETURNED_SQLSTATE		non-reserved	non-reserved	non-reserved
RETURNING	reserved, requires AS	non-reserved	non-reserved
RETURNS	non-reserved	reserved	reserved
REVOKE	non-reserved	reserved	reserved	reserved
RIGHT	reserved (can be function or type)	reserved	reserved	reserved
ROLE	non-reserved	non-reserved	non-reserved
ROLLBACK	non-reserved	reserved	reserved	reserved
ROLLUP	non-reserved	reserved	reserved
ROUTINE	non-reserved	non-reserved	non-reserved
ROUTINES	non-reserved
ROUTINE_CATALOG		non-reserved	non-reserved
ROUTINE_NAME		non-reserved	non-reserved
ROUTINE_SCHEMA		non-reserved	non-reserved
ROW	non-reserved (cannot be function or type)	reserved	reserved
ROWS	non-reserved	reserved	reserved	reserved
ROW_COUNT		non-reserved	non-reserved	non-reserved
ROW_NUMBER		reserved	reserved
RULE	non-reserved
RUNNING		reserved
SAVEPOINT	non-reserved	reserved	reserved
SCALAR		non-reserved
SCALE		non-reserved	non-reserved	non-reserved
SCHEMA	non-reserved	non-reserved	non-reserved	reserved
SCHEMAS	non-reserved
SCHEMA_NAME		non-reserved	non-reserved	non-reserved
SCOPE		reserved	reserved
SCOPE_CATALOG		non-reserved	non-reserved
SCOPE_NAME		non-reserved	non-reserved
SCOPE_SCHEMA		non-reserved	non-reserved
SCROLL	non-reserved	reserved	reserved	reserved
SEARCH	non-reserved	reserved	reserved
SECOND	non-reserved, requires AS	reserved	reserved	reserved
SECTION		non-reserved	non-reserved	reserved
SECURITY	non-reserved	non-reserved	non-reserved
SEEK		reserved
SELECT	reserved	reserved	reserved	reserved
SELECTIVE		non-reserved	non-reserved
SELF		non-reserved	non-reserved
SEMANTICS		non-reserved
SENSITIVE		reserved	reserved
SEQUENCE	non-reserved	non-reserved	non-reserved
SEQUENCES	non-reserved
SERIALIZABLE	non-reserved	non-reserved	non-reserved	non-reserved
SERVER	non-reserved	non-reserved	non-reserved
SERVER_NAME		non-reserved	non-reserved	non-reserved
SESSION	non-reserved	non-reserved	non-reserved	reserved
SESSION_USER	reserved	reserved	reserved	reserved
SET	non-reserved	reserved	reserved	reserved
SETOF	non-reserved (cannot be function or type)
SETS	non-reserved	non-reserved	non-reserved
SHARE	non-reserved
SHOW	non-reserved	reserved
SIMILAR	reserved (can be function or type)	reserved	reserved
SIMPLE	non-reserved	non-reserved	non-reserved
SIN		reserved
SINH		reserved
SIZE		non-reserved	non-reserved	reserved
SKIP	non-reserved	reserved
SMALLINT	non-reserved (cannot be function or type)	reserved	reserved	reserved
SNAPSHOT	non-reserved
SOME	reserved	reserved	reserved	reserved
SORT_DIRECTION		non-reserved
SOURCE		non-reserved	non-reserved
SPACE		non-reserved	non-reserved	reserved
SPECIFIC		reserved	reserved
SPECIFICTYPE		reserved	reserved
SPECIFIC_NAME		non-reserved	non-reserved
SQL	non-reserved	reserved	reserved	reserved
SQLCODE				reserved
SQLERROR				reserved
SQLEXCEPTION		reserved	reserved
SQLSTATE		reserved	reserved	reserved
SQLWARNING		reserved	reserved
SQRT		reserved	reserved
STABLE	non-reserved
STANDALONE	non-reserved	non-reserved	non-reserved
START	non-reserved	reserved	reserved
STATE		non-reserved	non-reserved
STATEMENT	non-reserved	non-reserved	non-reserved
STATIC		reserved	reserved
STATISTICS	non-reserved
STDDEV_POP		reserved	reserved
STDDEV_SAMP		reserved	reserved
STDIN	non-reserved
STDOUT	non-reserved
STORAGE	non-reserved
STORED	non-reserved
STRICT	non-reserved
STRING		non-reserved
STRIP	non-reserved	non-reserved	non-reserved
STRUCTURE		non-reserved	non-reserved
STYLE		non-reserved	non-reserved
SUBCLASS_ORIGIN		non-reserved	non-reserved	non-reserved
SUBMULTISET		reserved	reserved
SUBSCRIPTION	non-reserved
SUBSET		reserved
SUBSTRING	non-reserved (cannot be function or type)	reserved	reserved	reserved
SUBSTRING_REGEX		reserved	reserved
SUCCEEDS		reserved	reserved
SUM		reserved	reserved	reserved
SUPPORT	non-reserved
SYMMETRIC	reserved	reserved	reserved
SYSID	non-reserved
SYSTEM	non-reserved	reserved	reserved
SYSTEM_TIME		reserved	reserved
SYSTEM_USER		reserved	reserved	reserved
T		non-reserved	non-reserved
TABLE	reserved	reserved	reserved	reserved
TABLES	non-reserved
TABLESAMPLE	reserved (can be function or type)	reserved	reserved
TABLESPACE	non-reserved
TABLE_NAME		non-reserved	non-reserved	non-reserved
TAN		reserved
TANH		reserved
TEMP	non-reserved
TEMPLATE	non-reserved
TEMPORARY	non-reserved	non-reserved	non-reserved	reserved
TEXT	non-reserved
THEN	reserved	reserved	reserved	reserved
THROUGH		non-reserved
TIES	non-reserved	non-reserved	non-reserved
TIME	non-reserved (cannot be function or type)	reserved	reserved	reserved
TIMESTAMP	non-reserved (cannot be function or type)	reserved	reserved	reserved
TIMEZONE_HOUR		reserved	reserved	reserved
TIMEZONE_MINUTE		reserved	reserved	reserved
TO	reserved, requires AS	reserved	reserved	reserved
TOKEN		non-reserved	non-reserved
TOP_LEVEL_COUNT		non-reserved	non-reserved
TRAILING	reserved	reserved	reserved	reserved
TRANSACTION	non-reserved	non-reserved	non-reserved	reserved
TRANSACTIONS_​COMMITTED		non-reserved	non-reserved
TRANSACTIONS_​ROLLED_​BACK		non-reserved	non-reserved
TRANSACTION_ACTIVE		non-reserved	non-reserved
TRANSFORM	non-reserved	non-reserved	non-reserved
TRANSFORMS		non-reserved	non-reserved
TRANSLATE		reserved	reserved	reserved
TRANSLATE_REGEX		reserved	reserved
TRANSLATION		reserved	reserved	reserved
TREAT	non-reserved (cannot be function or type)	reserved	reserved
TRIGGER	non-reserved	reserved	reserved
TRIGGER_CATALOG		non-reserved	non-reserved
TRIGGER_NAME		non-reserved	non-reserved
TRIGGER_SCHEMA		non-reserved	non-reserved
TRIM	non-reserved (cannot be function or type)	reserved	reserved	reserved
TRIM_ARRAY		reserved	reserved
TRUE	reserved	reserved	reserved	reserved
TRUNCATE	non-reserved	reserved	reserved
TRUSTED	non-reserved
TYPE	non-reserved	non-reserved	non-reserved	non-reserved
TYPES	non-reserved
UESCAPE	non-reserved	reserved	reserved
UNBOUNDED	non-reserved	non-reserved	non-reserved
UNCOMMITTED	non-reserved	non-reserved	non-reserved	non-reserved
UNCONDITIONAL		non-reserved
UNDER		non-reserved	non-reserved
UNENCRYPTED	non-reserved
UNION	reserved, requires AS	reserved	reserved	reserved
UNIQUE	reserved	reserved	reserved	reserved
UNKNOWN	non-reserved	reserved	reserved	reserved
UNLINK		non-reserved	non-reserved
UNLISTEN	non-reserved
UNLOGGED	non-reserved
UNMATCHED		reserved
UNNAMED		non-reserved	non-reserved	non-reserved
UNNEST		reserved	reserved
UNTIL	non-reserved
UNTYPED		non-reserved	non-reserved
UPDATE	non-reserved	reserved	reserved	reserved
UPPER		reserved	reserved	reserved
URI		non-reserved	non-reserved
USAGE		non-reserved	non-reserved	reserved
USER	reserved	reserved	reserved	reserved
USER_​DEFINED_​TYPE_​CATALOG		non-reserved	non-reserved
USER_​DEFINED_​TYPE_​CODE		non-reserved	non-reserved
USER_​DEFINED_​TYPE_​NAME		non-reserved	non-reserved
USER_​DEFINED_​TYPE_​SCHEMA		non-reserved	non-reserved
USING	reserved	reserved	reserved	reserved
UTF16		non-reserved
UTF32		non-reserved
UTF8		non-reserved
VACUUM	non-reserved
VALID	non-reserved	non-reserved	non-reserved
VALIDATE	non-reserved
VALIDATOR	non-reserved
VALUE	non-reserved	reserved	reserved	reserved
VALUES	non-reserved (cannot be function or type)	reserved	reserved	reserved
VALUE_OF		reserved	reserved
VARBINARY		reserved	reserved
VARCHAR	non-reserved (cannot be function or type)	reserved	reserved	reserved
VARIADIC	reserved
VARYING	non-reserved, requires AS	reserved	reserved	reserved
VAR_POP		reserved	reserved
VAR_SAMP		reserved	reserved
VERBOSE	reserved (can be function or type)
VERSION	non-reserved	non-reserved	non-reserved
VERSIONING		reserved	reserved
VIEW	non-reserved	non-reserved	non-reserved	reserved
VIEWS	non-reserved
VOLATILE	non-reserved
WHEN	reserved	reserved	reserved	reserved
WHENEVER		reserved	reserved	reserved
WHERE	reserved, requires AS	reserved	reserved	reserved
WHITESPACE	non-reserved	non-reserved	non-reserved
WIDTH_BUCKET		reserved	reserved
WINDOW	reserved, requires AS	reserved	reserved
WITH	reserved, requires AS	reserved	reserved	reserved
WITHIN	non-reserved, requires AS	reserved	reserved
WITHOUT	non-reserved, requires AS	reserved	reserved
WORK	non-reserved	non-reserved	non-reserved	reserved
WRAPPER	non-reserved	non-reserved	non-reserved
WRITE	non-reserved	non-reserved	non-reserved	reserved
XML	non-reserved	reserved	reserved
XMLAGG		reserved	reserved
XMLATTRIBUTES	non-reserved (cannot be function or type)	reserved	reserved
XMLBINARY		reserved	reserved
XMLCAST		reserved	reserved
XMLCOMMENT		reserved	reserved
XMLCONCAT	non-reserved (cannot be function or type)	reserved	reserved
XMLDECLARATION		non-reserved	non-reserved
XMLDOCUMENT		reserved	reserved
XMLELEMENT	non-reserved (cannot be function or type)	reserved	reserved
XMLEXISTS	non-reserved (cannot be function or type)	reserved	reserved
XMLFOREST	non-reserved (cannot be function or type)	reserved	reserved
XMLITERATE		reserved	reserved
XMLNAMESPACES	non-reserved (cannot be function or type)	reserved	reserved
XMLPARSE	non-reserved (cannot be function or type)	reserved	reserved
XMLPI	non-reserved (cannot be function or type)	reserved	reserved
XMLQUERY		reserved	reserved
XMLROOT	non-reserved (cannot be function or type)
XMLSCHEMA		non-reserved	non-reserved
XMLSERIALIZE	non-reserved (cannot be function or type)	reserved	reserved
XMLTABLE	non-reserved (cannot be function or type)	reserved	reserved
XMLTEXT		reserved	reserved
XMLVALIDATE		reserved	reserved
YEAR	non-reserved, requires AS	reserved	reserved	reserved
YES	non-reserved	non-reserved	non-reserved
ZONE	non-reserved	non-reserved	non-reserved	reserved