HP Intelligent Management Center Standard Software Platform - Manual (Page 181)

Consideration 2
Any selection formula that is of the form: DataBaseField SupportedOp
erator ConstantOrParameterExpression
can be pushed down.
Of course DataBaseField is just a database field. SupportedOperator
is any of =, <>, <, <=, >, >=, StartsWith, Like or In.
ConstantOrParameterExpression is any expression that involves
constant values, operators, functions, and parameter fields. It cannot involve
variables, control structures, or fields other than parameter fields. By their
very definition, constant and parameter expressions can be evaluated without
accessing the database.
Note:
A constant or parameter expression can evaluate to a simple value, a range
value, an array value, or an array of range values. Here are some examples
of such expressions:
{?number parameter} - 3
Year ({?run date})
CurrentDate + 5
DateDiff ("q", CurrentDate, CDate("Jan 1, 1996"))
Month (Maximum ({?date range parameter}) + 15)
["Canada", "Mexico", "USA", {?enter a country}]
1000 To 5000
[5000 To 10000, 20000 To 30000, 50000 To 60000]
A complete example:
{Orders.Order Date} >= CurrentDate - 3
The program can also push down an expression that just contains a Boolean
field (without the operator and constant parts).
{Orders.Shipped}
Not {Orders.Shipped}
Consideration 3
IsNull (DataBaseField) can be pushed down.
Crystal Reports 2008 SP3 User's Guide 181
8 Designing Optimized Web Reports
Using enhanced record selection formulas