- Categories:
 Numeric functions (Logarithmic)
LOG¶
Returns the logarithm of a numeric expression.
- See also:
 
Syntax¶
LOG(<base>, <expr>)
Arguments¶
baseThe “base” to use (e.g. 10 for base 10 arithmetic).
This can be of any numeric data type (INTEGER, fixed-point, or floating point).
baseshould be greater than 0.baseshould not be exactly 1.0.exprThe value for which you want to know the log.
This can be of any numeric data type (INTEGER, fixed-point, or floating point).
exprshould be greater than 0.
Returns¶
Always returns a floating point number, even if one or more of the input expressions are of type integer or fixed-point.
Usage notes¶
If
baseis 1 or less than or equal to 0, an error is returned.If
expris less than or equal to 0, an error is returned.
Examples¶
SELECT x, y, log(x, y) FROM tab;
--------+--------+-------------+
   X    |   Y    |  LOG(X, Y)  |
--------+--------+-------------+
 2      | 0.5    | -1          |
 2      | 1      | 0           |
 2      | 8      | 3           |
 2      | 16     | 4           |
 10     | 10     | 1           |
 10     | 20     | 1.301029996 |
 10     | [NULL] | [NULL]      |
 [NULL] | 10     | [NULL]      |
 [NULL] | [NULL] | [NULL]      |
--------+--------+-------------+