Question about parameters and database storage

Hello, I was wondering about what these parameters meant

```
const Parameters kParameters{
.db_rows = 8,
.db_cols = 8,
.db_record_bit_size = 16,
.lwe_secret_dim = 1400,
.lwe_modulus_bit_size = 32,
.lwe_plaintext_bit_size = 8,
.lwe_error_variance = 8,
.linpir_params =
linpir::RlweParameters{
.log_n = 12,
.qs = {35184371884033ULL, 35184371703809ULL}, // 90 bits
.ts = {2056193, 1990657}, // 42 bits
.gadget_log_bs = {16, 16},
.error_variance = 8,
.prng_type = rlwe::PRNG_TYPE_HKDF,
.rows_per_block = 1024,
},
.prng_type = rlwe::PRNG_TYPE_HKDF,
};
```
Does the `lwe_plaintext_bit_size` have to be half the size of `db_record_bit_size`? Also wanted to know how the matrix that is assigned [here](https://github.com/google/hintless_pir/blob/4be2ae81a2a7999cd53f92a2c80f036ea3f7ab26/hintless_simplepir/database_hwy.cc#L65) related to the database index. Is it column-major ordering?