specify the condition for the table join operator by connecting the tables using the unique term number, which is skill_id in the result set of the text analysis and term_id in the taxonomy table.
in a non-federated environment, this is not generally an issue, as local resources (cpu, i/o) are usually adequately utilized by performing one leg or input of a union or join operator at a time.
generate the expression for the join predicate by applying the join operator to the expressions for the left and right attributes.
将联结操作符应用于左右属性的表达式,从而产生联结谓词的表达式。
as with the union operator, the join operator itself remains synchronous and is only able to process input from one leg of the join at a time.
和union操作符一样,连接操作符本身是同步的,每次只能处理来自连接操作符某一个分支的输入。
in a subsequent data flow operation, you'll use a join operator to ensure that full xml account records (contained in the info column) are fed into the target data warehouse table.