Error when prepared Statement in transaction mode

[pionoor]

Describe the bug
Preparing statement on a client connected to PgBouncer that runs in transaction mode does not have any issues. However, after switching to pgCat with the configs below:

[general]

host = "0.0.0.0"
port = 6432
admin_username = "pgcat"
admin_password = "pgcat"
prepared_statements = true
prepared_statements_cache_size = 50000

[pools.solana]
[pools.solana.users.0]
username = "rpc-server"
password = "pass"
pool_size = 400
min_pool_size = 10
pool_mode = "transaction"

[pools.solana.shards.0]
servers = [
  ["127.0.0.1", 5432, "primary"]
]
database = "slna"

Caused the application to error out while preparing some of the statements. Here Are application log which shows which statement is failed to be prepared at:

[2024-05-04T03:15:33.019846000Z INFO  rpc_server::postgres_client] Statement prepared successfully
[2024-05-04T03:15:33.065166000Z INFO  rpc_server::postgres_client] Statement prepared successfully
[2024-05-04T03:15:33.163112000Z INFO  rpc_server::postgres_client] Statement prepared successfully
[2024-05-04T03:15:33.208093000Z INFO  rpc_server::postgres_client] Statement prepared successfully
[2024-05-04T03:15:33.253698000Z INFO  rpc_server::postgres_client] Statement prepared successfully
[2024-05-04T03:15:33.298925000Z INFO  rpc_server::postgres_client] Statement prepared successfully
[2024-05-04T03:15:33.345800000Z INFO  rpc_server::postgres_client] Statement prepared successfully
[2024-05-04T03:15:33.394634000Z INFO  rpc_server::postgres_client] Statement prepared successfully
[2024-05-04T03:15:33.496065000Z INFO  rpc_server::postgres_client] Statement prepared successfully
[2024-05-04T03:15:33.541682000Z INFO  rpc_server::postgres_client] Statement prepared successfully

Could not connect to the Postgres server. Please review the configuration information. Error details: (Error in preparing the statement for PostgreSQL database, statment: SELECT t.*, COALESCE(
                            (SELECT block_time FROM block_confirmed_pool WHERE slot = t.slot),
                            (SELECT block_time FROM block_rooted WHERE slot = t.slot)
                        ) AS block_time
                        FROM transaction t
                        WHERE t.slot <= (SELECT slot FROM slot WHERE status = $1)
                        AND t.signature = $2; err: db error: ERROR: prepared statement "s21" does not exist)

To Reproduce
Not sure how without sharing the source code. But here are some snippets:

pub async fn new(conn_str: String) -> Result<Self> {
        let (client, conn) = tokio_postgres::connect(
            conn_str.as_str(), NoTls,
        ).await.map_err(|err| {
            anyhow!("Error in connecting to PostgreSQL database, conn_str: {}, error: {}", conn_str, err)
        })?;
        // Spawn a background task to handle the connection
        tokio::spawn(async move {
            if let Err(e) = conn.await {
                eprintln!("Error in connections: {}", e);
            }
        });
        let  get_transaction_stmt = prepare_statement(
                "SELECT t.*, COALESCE(
                            (SELECT block_time FROM block_confirmed_pool WHERE slot = t.slot),
                            (SELECT block_time FROM block_rooted WHERE slot = t.slot)
                        ) AS block_time
                        FROM transaction t
                        WHERE t.slot <= (SELECT slot FROM slot WHERE status = $1)
                        AND t.signature = $2;",
                   &client,
            ).await?;
   }
async fn prepare_statement(
    stmt: &str,
    client: &Client,
) -> Result<Statement> {
    let result = client.prepare(stmt).await;
    match result {
        Err(err) => {
            Err(anyhow!("Error in preparing the statement for PostgreSQL database, statment: {} err: {}", stmt, err))
        }
        Ok(statement) => {
            info!("Statement prepared successfully");
            Ok(statement)
        }
    }
}

Expected behavior
I expect all of the prepare statements operations to be successful when done on a client that is connected to pgCat that runs in transaction pool mode since it does that without errors with pgBouncer

Version: pgcat 1.1.2-dev4
OS: Ubuntu 22.04.4 LTS
postgres: psql (PostgreSQL) 16.2 (Ubuntu 16.2-1.pgdg22.04+1)
Pg Client lib: Rust, tokio_postgres 0.7

[Avinodh]

It doesn't seem like Pgcat supports Prepared Statements in Transaction Pooling Mode. Pgbouncer got support for this recently in version 1.21.0 (release)