Ranking High in Kaggle Competition is a Huge Advantage for Job Seekers

For someone who is looking for a job in data analytics field, high rankings in Kaggle Competition will give him tremendous advantage. Employers see the competition winners having strong problem solving skills and hands-on expertise. Indeed, to be able to complete some projects for Kaggle competitions, participants have to put in a lot of effort to deal with data issues even before any predictive models can be built. This is very similar to that in the real world applications where 80% of time is spent on data cleanse and manipulation. It is not a surprise that some employers prefer Kaggle competition winners over PhD graduates whose skills are perceived as more theoretical.

Taking my nephew, Yuyu Zhou, as an example. He got a master degree in data analytics. While he was in school, he spent a few weeks with other classmates to participate in Kaggle competitions. His team has achieved the top 3% and 5% in two Kaggle prediction competitions respectively (see my blog post a Young Data Scientist- Kaggle Competition Top 5% Winner: Yuyu Zhou. Once he graduated, he was quickly hired by a prestigious company and has been earning PhD level salary. Those few weeks he spent on Kaggle Competition was the best time investment of his life.

Oracle Ora_Hash function- Part 1 Random Sampling

Oracle ora_hash() is a very useful function. I have used it for different purposes such as generating random number. The following query generate 5 buckets from 0 to 4, each of them have the similar number of records.
First, we create a table and populate it with 1,000 numbers.

create table t_n (n number);

begin
for i in 1..1000
 loop 
 insert into t_n values(i);
 end loop;
 commit;
end;

In the query below, the parameter 5 of ora_hash defines the number of buckets is 5. As we see, each bucket has simlilar number of records.

with tbl as
(
select ora_hash(n, 5) bucket, n  from t_n)
select bucket, count(*), min(n), max(n) from tbl
group by bucket order by 1;
BBUCKET COUNT(*) MIN(N) MAX(N)
0 154          2  993
1 164          7  999
2 168          6  991
3 175          4  995
4 173          8 1000