UHCL 36a Graduate Database Course - Linear Hashing - Part 1

This video corresponds to the unit 7 notes for a graduate database (DBMS) course taught by Dr. Gary D. Boetticher at the University of Houston - Clear Lake (UHCL). The focus is on physical database design. This video looks at linear hashing. This is part 1 of 2.

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[KupiDante]

Thanks you for this useful video

[hac1m]

how do you know which hash function to use? After he adds 10 and there are buckets 0-2 he says bucket 0 and 2 use mod4 but bucket 1 still uses mod2. How do you know which hash function to use before you actually hash it....?

[axkibe]

He says you need to check all elements if they fall into the new bucket. But IMHO the key idea to linear hashing is you do not have to check all elements in case of a split. You only need to redistribute the elements in the Bucket (including its overflows) which is splitted. Otherwise the table would get much slower the larger it gets.

[1ma4ighter]

could you please tell me why or/and how they increase and when i would do it please, thanks

[1ma4ighter]

hey Gary, great video, i'm doin some late studying and this video helped majorly, i'm from south africa btw, there's just one thing i don't understand though :: i AM writing this evening after work but i'd still like to know: - innitially we would calculate the position of the value to add using (v mod 2), after the split happened the n pointer moved on bucket down and the value to mod with increased (2fold | by2)? ie: 4, but remained the same for the bucket to split ie: 2.

[Malaari]

Thank you for making these videos, they are great :)

[cawker1984]

Another lifesaver!

Thanks again Gary and keep these great vids coming :)