| Oracle® Database SQL Language Reference 11g Release 2 (11.2) Part Number E10592-02 | 
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Syntax

Purpose
LOG returns the logarithm, base n2, of n1. The base n1 can be any positive value other than 0 or 1 and n2 can be any positive value.
This function takes as arguments any numeric data type or any nonnumeric data type that can be implicitly converted to a numeric data type. If any argument is BINARY_FLOAT or BINARY_DOUBLE, then the function returns BINARY_DOUBLE. Otherwise the function returns NUMBER.
See Also:
Table 3-10, "Implicit Type Conversion Matrix" for more information on implicit conversionExamples
The following example returns the log of 100:
SELECT LOG(10,100) "Log base 10 of 100" FROM DUAL;
Log base 10 of 100
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