EQL reserves certain keywords for its exclusive use.
DEFINE Input AS SELECT DimDate_CalendarYear AS "Year", DimDate_MonthNumberOfYear AS "Month", ...
However, as a rule of thumb it is recommended that you do not name any identifier with a name that is the same as a reserved word.
AND | DAY_OF_WEEK | HAVING | OR | SYSDATE |
AS | DAY_OF_YEAR | HOUR | ORDER | SYSTIMESTAMP |
ASC | DEFINE | IN | PAGE | THEN |
BETWEEN | DESC | IS | PERCENT | TRUE |
BY | ELSE | JOIN | QUARTER | WEEK |
CASE | END | JULIAN_DAY_NUMBER | RETURN | WHEN |
CROSS | EVERY | LEFT | RIGHT | WHERE |
CUBE | FALSE | MINUTE | ROLLUP | YEAR |
CURRENT_DATE | FROM | MONTH | SECOND | |
CURRENT_TIMESTAMP | FULL | NOT | SELECT | |
DATE | GROUP | NULL | SETS | |
DAY_OF_MONTH | GROUPING | ON | SOME |
In addition, MEMBERS and SATISFIES are keywords that are reserved for future use (and as such, are not documented in this guide).
Keep in mind that function names (such as COUNT and STRING_JOIN) are not keywords and, therefore, could be used as identifiers. However, as a best practice, you should also avoid using function names as identifiers.