Should Prepare use query as Prepare Name?

[zhixinwen]

We are using the crate to talk to CRDB, and we notice the CRDB server memory is constantly growing. We think the issue is due to every time we execute a query, the crate would prepare the query with a different name: https://github.com/sfackler/rust-postgres/blob/98f5a11bc0a8e451552d8941ffa078c7eb6cd60c/tokio-postgres/src/prepare.rs#L66.

Is this a valid choice to use int as name instead of query or something else? I dont think other lib is doing this, for example in go it is using query: https://github.com/lib/pq/blob/3d613208bca2e74f2a20e04126ed30bcb5c4cc27/conn.go#L917

[sfackler]

Prepared statements are closed when they are dropped: https://github.com/sfackler/rust-postgres/blob/master/tokio-postgres/src/statement.rs#L15-L26

If CRDB doesn't clean up resources when that happens, it seems like a bug in CRDB.

[zhixinwen]

Thanks for the reply. I am not very familiar with the Postgres protocols, but looks like DEALLOCATE is for releasing prepared statements, and CLOSE is for cursor.

[sfackler]

We don't close statements at the SQL layer, we close them at the protocol layer. https://www.postgresql.org/docs/16/protocol-flow.html#PROTOCOL-FLOW-EXT-QUERY

[zhixinwen]

Thank you!