SQL Hacks - Day 2

So, I restarted SQL on Leetcode! I will try to be more consistent now onwards, it is a promise!

Did you know the way you use "having" clause with group by can impact your performance?

Using Having count(*) as compared to having count(field_name) even if there is only 1 field cuts the time taken to run the query by ALMOST HALF!

So, try to use having count(*) instead of a particular field name.

I was in fix between group by, having and where - if I should use just where or use having

https://stackoverflow.com/questions/49758446/where-vs-having-performance-with-group-by

I am still not able to wrap my head around which is better - Group by + having or Where?

Let me know in the comments!

I plan to solve 3-4 questions everyday for the next 10 days just to build consistency.

I solved 4 questions today and now am good for the day (for SQL)

Catch up with y'all later!