log function

Returns the logarithm of expr with base.

Syntax 

log( [base,] expr)

Arguments

  • base: An optional expression that evaluates to a numeric.

  • expr: An expression that evaluates to a numeric.

Returns

A DOUBLE.

If base or expr are less than or equal to 0 the result is NULL. log(expr) is a synonym for ln(expr).

Examples 

> SELECT log(10, 100);
    2.0
> SELECT log(e());
    1.0