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.user`: the database username
 - `db.instance`: the database instance
 - `db.statement`: the SQL query
 - `db.type`: _sql_

The default tracing policy is `link:../../apidocs/io/vertx/core/tracing/TracingPolicy.html#PROPAGATE[PROPAGATE]`, the client
will only create a span when involved in an active trace.

You can change the client policy with `link:../../apidocs/io/vertx/sqlclient/SqlConnectOptions.html#setTracingPolicy-io.vertx.core.tracing.TracingPolicy-[setTracingPolicy]`,
e.g you can set `link:../../apidocs/io/vertx/core/tracing/TracingPolicy.html#ALWAYS[ALWAYS]` to always report
a span:

[source,java]
----
options.setTracingPolicy(TracingPolicy.ALWAYS);
----