ARROW-254: remove Bit type as it is redundant with Boolean

[julienledem]

The only use of Bit is for the nullability (or validity) vector which is best understood as a boolean type.
We should remove it as it is not used.

[jacques-n]

LGTM +1

[wesm]

+1. The Java build is failing for some reason

[julienledem]

retriggering the build...

[jihoonson]

I'm also suffering from this error, and found the reason. The BaseValueVector.MAX_ALLOCATION_SIZE value used in TestValueVector is declared as a static variable which means its value is initialized when the BaseValueVector class is loaded. Obviously, changing BaseValueVector.MAX_ALLOCATION_SIZE by setting the "arrow.vector.max_allocation_bytes" property in TestValueVector doesn't work. As a result, this test tries to allocate a very large array of the size of Integer.MAX_VALUE, which causes OOM.

I think that this test looks fragile, and thus we need to make the allocation size small. However, reducing the allocation size causes another problem. Many tests in TestValueVector expect the OversizedAllocationException when value allocation reaches to MAX_VALUE_ALLOCATION. So, reducing the allocation size makes OversizedAllocation tests difficult.

I would like to separate all these OversizedAllocation tests, but not sure this is a right way. Please give me some help.

[julienledem]

@jihoonson I created a JIRA for this: https://issues.apache.org/jira/browse/ARROW-260