Hi Sameer,
Nice to see you around!
The developer wanted to use HASH indexes as the query hitting some columns are only using equality comparison (=). They said that HASH has a speed of O(1) whereas B-Tree has a speed of logarithm. I believe it's true if you look fundamentally at hashtable and B-Tree algorithm.
However, I did my research and found that HASH index has minimal perfomance improvement over B-Tree in equality comparison.
Thus, we dropped the idea already :)
Cheers!