The SQL client can trace query execution when Vert.x has tracing enabled.

The client reports the following client spans:

- `Query` operation name

- tags

- `db.system`: the database management system product

- `db.user`: the database username

- `db.instance`: the database instance

- `db.statement`: the SQL query

- `db.type`: sql

The default tracing policy is `PROPAGATE`, the client will only create a span when involved in an active trace.

You can change the client policy with `setTracingPolicy`, e.g you can set `ALWAYS` to always report a span:

    options.setTracingPolicy(TracingPolicy.ALWAYS);