The following tables show how SQL-92 functions are supported in the Impala Query Language. Additional methods may be supported with JDBC Escapes.

Table 1. Set Functions Supported
Set Function Support in Impala SQL
Count Supported
AVG Supported
MIN Supported
MAX Supported
SUM Supported
DISTINCT Supported
ALL Supported
Table 2. 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 3. 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 4. Date/Time Functions Supported
Date/Time Function Support in Impala SQL
CURRENT_DATE( ) Not supported2
CURRENT_TIME( ) Not supported3
CURRENT_TIMESTAMP Not supported. Use UNIX_TIMESTAMP()4.
Table 5. System Functions Supported
System Function Support in Impala SQL
CASE ... END Supported.
COALESCE Supported.
NULLIF Not supported.5
CAST Supported.

Refer to Scalar functions in the Progress DataDirect for JDBC Drivers Reference for more information.

1 Supported by JDBC Escapes
2 Supported by JDBC Escapes
3 Supported by JDBC Escapes
4 Supported by JDBC Escapes
5 Supported by JDBC Escapes