#sql-database #sql #analytics #performance #client #high

monetdb

Client library for MonetDB, a high performance SQL database for analytics

1 unstable release

0.2.0 Oct 4, 2024

#448 in Database interfaces

MPL-2.0 license

185KB
4.5K SLoC

MonetDB bindings for Rust

Rust client for the MonetDB analytics database.

Note: this crate is in its early stages. The basics seem to work but a lot has not been implemented yet and the API may change in incompatible ways at any time.

Examples

use std::error::Error;
use monetdb::Connection;

fn main() -> Result<(), Box<dyn Error>> {
    let url = "monetdb:///demo?user=monetdb&password=monetdb";
    let conn = Connection::connect_url(url)?;
    let mut cursor = conn.cursor();

    cursor.execute("SELECT hostname, clientpid, client, remark FROM sys.sessions")?;
    while cursor.next_row()? {
        // getters return Option< >, None means NULL
        let hostname: Option<&str> = cursor.get_str(0)?;
        let clientpid: Option<u32> = cursor.get_u32(1)?;
        let client: Option<&str> = cursor.get_str(2)?;
        let remark: Option<&str> = cursor.get_str(3)?; // usually NULL
        println!("host={hostname:?} clientpid={clientpid:?} client={client:?} remark={remark:?}",);
    }
    Ok(())
}

// Example output:
// host=Some("totoro") clientpid=Some(1895691) client=Some("libmapi 11.51.4") remark=None
// host=Some("totoro") clientpid=Some(1914127) client=Some("monetdb-rust 0.1.1") remark=None

You can also use a Parameters object to fine tune the connection parameters:

# use std::error::Error;
use monetdb::{Parameters, Connection};
# fn main() -> Result<(), Box<dyn Error>> {
let parms = Parameters::basic("demo", "monetdb", "monetdb")? // database / user / password
    .with_autocommit(false)?;
let conn = Connection::new(parms)?;
# Ok(())
# }

Current status

  • Support for MonetDB Jun2020 (11.37.7) and higher. Older versions are highly likely to work but haven't been tested. If you need this, just ask.

  • Rust 1.80 and higher, older versions have not yet been tested.

  • The full monetdb:// connection URL syntax is supported, though not all features have been implemented.

  • Most data types can be retrieved in string form using get_str(). Exception: blobs

  • The primitive types bool, i8/u8, i16/u16, i32/u32, i64/u64, i128/u128, isize/usize, f32/f64 have typed getters, for example get_i8().

  • A single call to Cursor::execute() can return multiple result sets.

  • extremely basic and untested TLS (monetdbs://) support can optionally be compiled in.

Not implemented yet but planned:

  • parametrized queries

  • start transaction / commit / rollback

  • typed getters for decimal and temporal types

  • BLOB support

  • Full TLS support

  • file transfers

  • Binary result set

  • Adaptive paging window sizes

  • scanning /tmp for Unix Domain sockets

  • Non-SQL, for example language=mal for MonetDB's tracing / profiling API

  • PREPARE STATEMENT

  • Async, seems to be needed for sqlx

  • Integration with database frameworks such as sqlx and Diesel. There does not seem to be a JDBC equivalent for Rust.

Optional features

The monetdb crate currently defines one optional feature:

  • rustls Enable a first stab at supporting TLS connections using rustls. The TLS-related configuration parameters such as cert= and clientkey= aren't supported yet and there is no testing, but a basic monetdbs:// URL seems to work. To try it, pass it on the command line like this:
    cargo run --features=rustls --example testconnect -- monetdbs://my.tls.host/demo
    
    or enable it in your application's Cargo.toml like this:
    [dependencies]
    monetdb = { version="0.1.1", features=["rustls"]}
    

Dependencies

~8–20MB
~318K SLoC