Supported SQL Functionality : SQL Expressions : Functions

Functions

The following tables show how SQL-92 functions are supported in the Impala Query Language. Additional methods may be supported with JDBC Escapes. See "Scalar Functions" for more information.

Table 19. Set Functions Supported
Set Function	Support in Impala SQL
Count	Supported
AVG	Supported
MIN	Supported
MAX	Supported
SUM	Supported
DISTINCT	Supported
ALL	Supported

Table 20. Numeric Functions Supported
Numeric Function	Support in Impala SQL
CHAR_LENGTH CHARACTER_LENGTH	Not supported. Use LENGTH(string) instead.
Position...In	Not supported
BIT_LENGTH(s)	Not supported
OCTET_LENGTH(str)	Not supported
EXTRACT...FROM	Not supported

Table 21. String Functions Supported
String Function	Support in Impala SQL
Substring	Supported
Convert … using	Not supported
TRIM	Supported.
Leading	Not supported. Use LTRIM.
Trailing	Not supported. Use RTRIM.
Both	Not supported (default behavior of TRIM)

Table 22. Date/Time Functions Supported
Date/Time Function	Support in Impala SQL
CURRENT_DATE( )	Not supported¹
CURRENT_TIME( )	Not supported²
CURRENT_TIMESTAMP	Not supported. Use UNIX_TIMESTAMP()³.

¹ Supported by JDBC Escapes

² Supported by JDBC Escapes

³ Supported by JDBC Escapes

Table 23. System Functions Supported
System Function	Support in Impala SQL
CASE ... END	Supported.
COALESCE	Supported.
NULLIF	Not supported.¹
CAST	Supported.

¹ Supported by JDBC Escapes