[bowyakka]

On the continum of relational algebra to logic programming catalog is somewhere in the middle.

It is better at handling recursive queries, and logical inference than SQL. On the flip side SQL can be better at more set style operations (for instance windowing functions are painful in datalog).

It is different tooling, essentially it comes down to do you want to extract answers from your data with varying relational algebra but holding the logic the same (SQL), or keeping the relational algebra the same but varying the logic (datalog).

[aargh_aargh]

Could you please explain what you mean by "varying relational algebra/logic"? Didn't understand that at all. I only know SQL.