-
|
I don't understand mask in aggregation, does anyone understand it? |
Beta Was this translation helpful? Give feedback.
Replies: 1 comment 3 replies
-
|
It's used to implement filtered aggregations: https://trino.io/docs/current/functions/aggregate.html#filtering-during-aggregation The aggregation operator uses the mask column to determine whether to include the corresponding input in the aggregation function computation. |
Beta Was this translation helpful? Give feedback.
-
|
thank you very much martint, I get it |
Beta Was this translation helpful? Give feedback.
-
|
in this case, can we add a filterNode before aggregationNode in optimization phase? is it easier to understand? |
Beta Was this translation helpful? Give feedback.
-
|
it's a little hard to understand the mask |
Beta Was this translation helpful? Give feedback.
It's used to implement filtered aggregations: https://trino.io/docs/current/functions/aggregate.html#filtering-during-aggregation
The aggregation operator uses the mask column to determine whether to include the corresponding input in the aggregation function computation.