Reserved words in Db2 for z/OS

Restrictions exist on the use of certain words that are used by Db2 for z/OS®. In some cases, these names are reserved and cannot be used by application programs. In other cases, certain names are not recommended for use by application programs though not prevented from being used by the database manager.

Keywords can be used as ordinary identifiers, except in a context where they could also be interpreted as SQL syntax. When a keyword can be interpreted as SQL syntax the keyword is considered a reserved word in that context, which means that it cannot be used as an ordinary identifier. However, a keyword can be used as an identifier in a context where it is a reserved word, by specifying it as a delimited identifier. For example:

ALL cannot be a column name in a SELECT statement, unless it is delimited. However, if the quotation mark (") is the escape character that begins and ends delimited identifiers, “ALL” can be used as a column name in a SELECT statement.
COUNT cannot be used as a column name in a SELECT statement, unless it is also specified as delimited.

New reserved words for Db2 12 are identified by note ¹ in the following table. Some topics in this information might also indicate words that cannot be used in the specific context that is being described.

IBM® SQL has additional reserved words that Db2 for z/OS does not enforce. Therefore, you should not use these additional reserved words as ordinary identifiers in names that have a continuing use. For a list of the reserved words, see SQL Reference for Cross-Platform Development - Version 6 for a list of the words.

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Table 1. Reserved words in Db2 for z/OS
First letter	Reserved words
A	ADD AFTER ALL ALLOCATE ALLOW ALTER AND ANY AS ARRAY ARRAY_EXISTS ASENSITIVE ASSOCIATE ASUTIME AT AUDIT AUX AUXILIARY
B	BEFORE BEGIN BETWEEN BUFFERPOOL BY
C	CALL CAPTURE CASCADED CASE CAST CCSID CHAR CHARACTER CHECK CLONE CLOSE CLUSTER COLLECTION COLLID COLUMN COMMENT COMMIT CONCAT CONDITION CONNECT CONNECTION CONSTRAINT CONTAINS CONTENT CONTINUE CREATE CUBE CURRENT CURRENT_DATE CURRENT_LC_CTYPE CURRENT_PATH CURRENT_SCHEMA FL 504 CURRENT_SERVER¹ CURRENT_TIME CURRENT_TIMESTAMP FL 504 CURRENT_TIMEZONE¹ CURRVAL CURSOR
D	DATA DATABASE DAY DAYS DBINFO DECLARE DEFAULT DELETE DESCRIPTOR DETERMINISTIC DISABLE DISALLOW DISTINCT DO DOCUMENT DOUBLE DROP DSSIZE DYNAMIC
E	EDITPROC ELSE ELSEIF ENCODING ENCRYPTION END ENDING END-EXEC² ERASE ESCAPE EXCEPT EXCEPTION EXECUTE EXISTS EXIT EXPLAIN EXTERNAL
F	FENCED FETCH FIELDPROC FINAL FIRST FOR FREE FROM FULL FUNCTION
G	GENERATED GET GLOBAL GO GOTO GRANT GROUP
H	HANDLER HAVING HOLD HOUR HOURS
I	IF IMMEDIATE IN INCLUSIVE INDEX INHERIT INNER INOUT INSENSITIVE INSERT INTERSECT INTO IS ISOBID ITERATE
J	JAR JOIN
K	KEEP KEY
L	LABEL LANGUAGE LAST LC_CTYPE LEAVE LEFT LIKE LIMIT¹ LOCAL LOCALE LOCATOR LOCATORS LOCK LOCKMAX LOCKSIZE LONG LOOP
M	MAINTAINED MATERIALIZED MICROSECOND MICROSECONDS MINUTES MODIFIES MONTH MONTHS
N	NEXT NEXTVAL NO NONE NOT NULL NULLS NUMPARTS
O	OBID OF OFFSET¹ OLD ON OPEN OPTIMIZATION OPTIMIZE OR ORDER ORGANIZATION OUT OUTER
P	PACKAGE PADDED PARAMETER PART PARTITION PARTITIONED PARTITIONING PATH PIECESIZE PERIOD PLAN PRECISION PREPARE PREVVAL PRIOR PRIQTY PRIVILEGES PROCEDURE PROGRAM PSID PUBLIC
Q	QUERY QUERYNO
R	READS REFERENCES REFRESH RELEASE RENAME RESIGNAL REPEAT RESTRICT RESULT RESULT_SET_LOCATOR RETURN RETURNS REVOKE RIGHT ROLE ROLLBACK ROLLUP ROUND_CEILING ROUND_DOWN ROUND_FLOOR ROUND_HALF_DOWN ROUND_HALF_EVEN ROUND_HALF_UP ROUND_UP ROW ROWSET RUN
S	SAVEPOINT SCHEMA SCRATCHPAD SECOND SECONDS SECQTY SECURITY SEQUENCE SELECT SENSITIVE SESSION_USER SET SIGNAL SIMPLE SOME SOURCE SPECIFIC STANDARD STATIC STATEMENT STAY STOGROUP STORES STYLE SUMMARY SYNONYM SYSDATE SYSTEM SYSTIMESTAMP
T	TABLE TABLESPACE THEN TO TRIGGER TRUNCATE TYPE
U	UNDO UNION UNIQUE UNTIL UPDATE USER USING
V	VALIDPROC VALUE VALUES VARIABLE VARIANT VCAT VERSIONING VIEW VOLATILE VOLUMES
W	WHEN WHENEVER WHERE WHILE WITH WLM
X	XMLCAST XMLEXISTS XMLNAMESPACES
Y	YEAR YEARS
Z	ZONE

Notes:

New reserved word for Db2 12.
COBOL only

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