- Categories:
Numeric functions (Logarithmic)
LOG¶
Returns the logarithm of a numeric expression.
- See also:
Syntax¶
LOG(<base>, <expr>)
Arguments¶
base
The “base” to use (e.g. 10 for base 10 arithmetic).
This can be of any numeric data type (INTEGER, fixed-point, or floating point).
base
should be greater than 0.base
should not be exactly 1.0.expr
The value for which you want to know the log.
This can be of any numeric data type (INTEGER, fixed-point, or floating point).
expr
should 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
base
is 1 or less than or equal to 0, an error is returned.If
expr
is 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] |
--------+--------+-------------+