Outsystems provides Aggregates to fetch data using an optimized query. 

Implicit conversion occurs when Outsystems Aggregates needs to automatically convert some portion of data from one data type to another, when they are compatible.

What sometimes happens is that Outsystems Converts the Attributes from Entities to the data type of, for example, a local variable. Since this is not explicit or alerted to the developer, performance issues may appear without knowing in what part of the query the issue is comming from.

It would be nice that Outsystems could inform or alert developers for Implicit Attributes Convertions so code improvements could be made.

Example: In this scenario, the parameter @qploDMPRKB is LongInteger and DMPRKA Integer:

SELECT NULL o0, NULL o1, NULL o2, [ENZI671T].[DMPRKA] o3, NULL o4, NULL o5, NULL o6)  FROM {ZI671T} [ENZI671T]  WHERE (convert(bigint, [ENZI671T].[DMPRKB]) = @qploDMPRKB)