Aggregation Query

Question

Hi, 
 Wanted to understand on how Appian parses an Expression Rule that uses a!queryAggregation and a!queryAggregationColumn against a Table/View? Does it convert and send a query as-is with GROUP By to the database SQL engine or does it get the data and then do the grouping on-fly in its memory? 
 Thank you in advance for your response.

Mike Schmitt · Accepted Answer

It's intentionally obfuscated through the Appian-based abstraction layer (the data store, at least for the older data types), particularly so that they can shift things around in the back-end on a progressive basis to tweak efficiency without breaking the way things work on the Designer front-end. That's all a long way of saying, we don't "officially" have any way of directly knowing what the exact SQL is that eventually gets passed to the DB via the Appian query, but it's reasonably safe to assume that by now they've probably fine-tuned it to be reasonably close to the most efficient thing possible.

Jones Prakash Selvaraj · Answer

Hi ougdp2003 , 
 I have recently come across a video on YouTube similar to this. Sharing it here might help - CTTO

Stefan Helzle · Answer

Aggregations are translated into SQL statements and sent to the DB for execution.

Harshit Bumb (Appyzie) · Answer

Aggregation and filtering happen on the Database level.

Konduru Chaitanya · Answer

Hello ougdp2003 , Your query aggregation is used as an SQL statement for execution.

Abhishek Karumuru · Answer

Appian translates the expression into a corresponding SQL query and sends it to the database. 
 When these aggregation functions are used, Appian generates SQL queries that include GROUP BY clauses, and these queries are sent to the database engine for execution. Appian does not bring all the data into its memory and then perform grouping on it.

Aggregation Query

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