pgcat: Enormous performance regression by PR #482 when prepared_statements is set to true

Describe the bug I wanted to try out prepared statement support and measure its performance in pgcat (essentially reproducing the blog). But when running pgbench --select-only on the main branch I was only able to get ~50 TPS.

To Reproduce Steps to reproduce the behavior:

1. git checkout main
2. Add prepared_statements = true to the minimal config
3. RUST_LOG=info cargo run --release -- pgcat.minimal.toml
4. pgbench --select-only -T 10 -P 1 -p 6433 --protocol prepared

Expected behavior Get somewhere in the order of 2000-20000 TPS. But instead I get between 20-50TPS. The worst part is that this even happens when using --protocol simple. Only if you enable prepared_statements = true from the config, performance of --protocol simple returns to normal levels.

Screenshots I narrowed the regression down commit: 4b78af9676596135bfcf16b049f4b1649a9064ed With commit: 4b78af9676596135bfcf16b049f4b1649a9064ed

With commit right before: 73500c0c961a57ae3bac0618046775a43ea78129

Desktop (please complete the following information):

• OS: Linux

Additional info The reason I was testing pgcat its performance was because I wanted to compare PgBouncer its upcoming prepared statement support (https://github.com/pgbouncer/pgbouncer/pull/845) to pgcat and Odyssey. But pgcat its perf was so much lower than expected that something obviously seemed wrong.