EXPORT PhysicalType STORE(LogicalType alias) := expression;

PhysicalTypeThe value type of the resulting output of the function.
LogicalTypeThe value type of the input parameter to the function.
aliasThe name of the input to use in the expression.
expressionThe operation to perform on the input.

STORE defines the callback function to be applied to the computed value to store it within the record. This function defines how the system writes the data to disk.