spl-token-2022 PodMint and Mint or PodAccount and Account usage

Question

In tokens extensions while using the rust library https://docs.rs/spl-token-2022 when should I use

1. PodMint instead of Mint
2. PodAccount instead of Account

I am a bit confused because for example, the length of the PodMint and Mint is the same while initializing a mint and paying for rent

let extensions = [ExtensionType::InterestBearingConfig];
let mint_len = ExtensionType::try_calculate_account_len::<Mint>(&extensions).unwrap();
let pod_mint_len = ExtensionType::try_calculate_account_len::<PodMint>(&extensions).unwrap();
println!("MINT LENGTH = {}", mint_len);
println!("POD MINT LENGTH = {}", pod_mint_len);
// This is printed in the console
// MINT LENGTH = 222
// POD MINT LENGTH = 222

This shows that the same amount of memory is allocated when creating the mint, so where would I use the Pod types (PodMint, PodAccount)

Answer 1

The concept of PodMint vs Mint is to allow for in-place / zero-copy deserialization, which uses much fewer compute units on-chain. If you want to do things in-place, then you can use the Pod variants. If you want to copy the data out of the account, then you can use the non-pod variants.