Accessing databases in other Namespaces

Sure. There are two ways:

1. Switch to another namespace to execute your query:

/// Get a list of all mirrored databases as a $lb()
ClassMethod GetMirroredDBs() As %List
{
    new $namespace
    set $namespace = "%SYS"
    set sql = "SELECT LIST(Name) dbs FROM Config.Databases_MirrorDatabaseList()"
    set rs = ##class(%SQL.Statement).%ExecDirect(,sql)
    do rs.%Next()
    set dbs = $lfs(rs.dbs)
    kill rs
    quit dbs
}

Now you can have this method in USER namespace and it would automatically swith into %SYS, execute query, iterate over the results, write results into a local variable, switch back into USER namespace and return the value back to you.

The main thing you need to remember is that result set iteration MUST happen in a target namespace.

2. Map classes and globals to your namespace. Docs. Table would be available as if it was created in your original namespace.