Re: A question about understanding Symbol tables and Bit-Stuffed tables in how QlikView stores data
I've tried to post some more details, but I am blocked by this awesome forum software to do so.
Binary representation is using power of two. So 3 bits = 8 possible values, one more bit doubles the value range:
4 bits = 16 possible values. And so forth.
So you would need only 4 bits to encode up to 16 distinct values.
I think the images above are kind of misleading when looking at the length of the pointer and the number of visible distinct values. The dots at the bottom should probably denote that many more symbols may follow, but since there are no dots at the top, I wonder why the bit pointer starts with an offset. Maybe it's explained in the blog, I would need to review it. For the amount of values we see, each symbol tables would need 1 bits for the pointers (if zero and one could be used for encoding).