Question

I am trying to rewrite this block with simpler logic if this can be done. I am using it within a larger SELECT statement and I think IF I can simplify this block, I might be able to improve performance of my query.

proj_catg_type_id, proj_catg_id and proj_id are all PKs in their tables.

select  t1.proj_catg_name
from    table1 t1, table2 t2, table3 t3
where   t2.proj_catg_type_id = t1.proj_catg_type_id
and     t2.proj_catg_type_id = 213
and     t3.proj_id = t2.proj_id

Answer 1

Without knowing the referential integrety rules and the logic behind the tables it is difficult to give a 100% correct answer. But just by looking to this statement the most simplified logic would be

select t1.proj_catg_name
from    table1 t1
where   t1.proj_catg_type_id = 213;