Does dagster use connection pooling for its postgres backend?

Yes, Dagster does use connection pooling for its Postgres backend. However, it's important to note that the connection pool size is limited to 1 to prevent data leakage across threads. This means that while there is a connection pool, it effectively allows only one connection at a time. This can lead to the creation of multiple connections per page load when using Dagit, as many pages make concurrent queries. This behavior has been noted in discussions around the high volume of Postgres connections from Dagit queries. Users have found that using external solutions like pgBouncer for connection pooling can help mitigate the issue and improve performance.

could you provide more detail about the data leakage issue?