Configuration meta_client

[levcom]

As well as meta_client for standalone configuration (single process)

frontend: FrontendOptions {
        mode: Standalone,
...
        meta_client: None,
...
}

I wanted to connect MetaClient to my program and use DatafusionQueryEngine.
For example, in my program I want to execute several queries that return RecordBatches and perform join, projects ops, mathematical ops with them (with DatafusionQueryEngine).

[killme2008]

Hi,

I am sorry that I don't get the point. Could you please provide a more detailed description of your question?

[levcom]

I want to execute multiple queries on a database to get some results. Then, I want to perform additional queries on these results for merging, filtering, and more. To do this, I plan to use the DatafusionQueryEngine for post-processing in my Rust program. But to create a DatafusionQueryEngine instance, I need to connect a MetaClient. However, the address for the MetaClient is not provided in the standalone configuration (it’s set to meta_client: None), and I’m not sure how to set it up.

`
let grpc_addr = "127.0.0.1:4001";
let client = Client::with_urls([grpc_addr]);
let db = Database::new(DEFAULT_CATALOG_NAME, DEFAULT_SCHEMA_NAME, client);

    let res1 = database.sql(&query1).await.unwrap();
    let res2 = database.sql(&query2).await.unwrap();

    // join res1 and res2 filter and project

    // meta_addr - undefinded !!!
    let mut meta_client = MetaClientBuilder::default().enable_store().build();
    meta_client.start([meta_addr]).await.unwrap();
    let meta_client = Arc::new(meta_client);
    ...
    let engine = DatafusionQueryEngine::new(state, _)

`

[killme2008]

If I understand correctly, you can set the meta client to None when in standalone mode.