Operators and Functions
Operators and functions can be used to transform columns before being synchronized to a client.
When filtering on parameters (token parameters in the case of parameter queries, and bucket parameters in the case of data queries), operators can only be used in a limited way. Typically only
IS NULLare allowed on the parameters, and special limits apply when combining clauses with
NOT. The exact rules are still being refined — make sure to validate and test the sync rules.
When transforming output columns, or filtering on row values, those restrictions do not apply.
Some fundamental restrictions on these operators and functions are:
- 1.It must be deterministic — no random or time-based functions.
- 2.No external state can be used.
- 3.It must operate on data available within a single row. For example, no aggregation functions allowed.