Details

Type: Task

Status: Closed

Priority: Minor

Resolution: Fixed

Affects Version/s: 10.10.1.1

Fix Version/s: 10.10.1.1

Component/s: Documentation

Labels:None
Description
The limits for floatingpoint values have changed as a result of DERBY3398 and should be documented:
Smallest DOUBLE: 4.9e324 (aka Double.MIN_VALUE)
Largest DOUBLE: 1.7976931348623157e+308 (aka Double.MAX_VALUE)
Smallest positive DOUBLE: 2.2250738585072014E308 (aka Double.MIN_NORMAL)
Largest negative DOUBLE: 2.2250738585072014E308
Smallest REAL: 1.4e45 (aka Float.MIN_VALUE)
Largest REAL: 3.4028235e+38 (aka Float.MAX_VALUE)
Smallest positive REAL: 1.17549435E38 (aka Float.MIN_NORMAL)
Largest negative REAL: 1.17549435E38
Issue Links
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DERBY3398 Support min/max values for Java types float/double in real/double columns
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Thanks for the info about the values, Knut.
The terms "smallest" and "largest" seem to have been used in our documentation to refer to positions on a number line, where "smallest" means "farthest to the left" and "largest" means "farthest to the right". So we have been saying that the "Smallest DOUBLE" was 1.79769E+308, while the "Largest DOUBLE" was the positive version of that, 1.79769E+308. Similarly, we called 2.225E307 the "Largest negative DOUBLE" because it's closest to zero.
This is confusing because we (I, anyway?) usually think of "smallest" and "largest" as referring to magnitude, as defined by whether the exponent is negative or positive. So the closer a number is to zero the smaller it is, whether negative or positive. The Java API docs for java.lang.Double and java.lang.Float use this terminology. I think I'll try to get closer to the language used there. This will involve using the terms "normalized" and "denormalized", but I don't think that's a major issue.