- 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] |
--------+--------+-------------+