Good thinking! Since regex might not cover all edge cases (delete within a CTE for example), it is best to implement a proper SQL parser in kernel, you would ne

Good thinking! Since regex might not cover all edge cases (delete within a CTE for example), it is best to implement a proper SQL parser in kernel, you would need to be able to stitch together TCP frames and then attempt to parse; then an AST walk can tell if your query has any mutations or not. One extra edge case to take care of is non standard ports used for PostgreSQL. Rather than trying to make our solution work with them, it would be more prudent to segfault on any attempts of PostgreSQL processes to bind to non-5432 ports though (fail early)