Improve the performance of table functions To improve the performance of table functions, force more efficient join orders for queries which use table functions. Functionstable functions Optimizertable function performance

The optimizer makes hard-coded guesses about how to calculate the cost of a user-written -style table function. For this reason, the optimizer may place a table function in an inefficient position in the join order. You can give the optimizer more information so that it makes better choices. See "Programming -style table functions" in the for details.

Using restricted table functions can also improve performance greatly. See "Writing restricted table functions" in the .