I never knew that I was a good mentor at SQL , specially at PL/SQL.

I gave a task to a new member of my team, to fill 5 tables with data from other 15 tables.

I informed him well about data table info and structure. He spended about 3 days to create 25 different queries in order to fill 5 tables.

After I saw the 25 queries, I told him, that he could do it with 1 main query and 5 insert statements.

So I spended 1 hour of training, in order to build,run and explain how to create the best sql statements for this task.

(First 5 minutes)
It was looking so simple at the beginning from starting with 1 simple join, after some steps he lost my actions.

(Rest 55 minutes)
I was explained the sql statements I 've created and how Oracle works.

Now , every time he meets me, he feels so thankful for learning him all those Oracle sql tips in 1 hour.

Now he is working only with big data and he loves the sql.