User`s guide

Transformation components
98 Sybase IQ ETL 4.1
Using lookups in the Data Calculator
The Data Calculator can perform lookups on attribute level. The lookup data
has to be provided at special lookup ports.
Adding Lookup Ports
To add a lookup port to a Data Calculator component, connect the output port
of the data providing component with the Data Calculator component. Or, you
can select Add Input Port from the Data Calculator component menu and
connect the output port of the data providing component with the new port.
The number of lookup ports is unlimited.
Preparing the lookup data
Each lookup port must have at least two attributes. The first attribute represents
the key, all other attributes the return values.
If you need to lookup compound keys you have to concatenate the key values
within a preceding component and use the same kind of concatenation on the
key expression for the lookup.
Setting general lookup options
You can use the Lookup Options property to configure the lookup. The Enter
Property window will display a list of all lookup ports and its current option
values.
The properties are:
• Lookup Name — The Lookup name is inherited from the associated port
and cannot be changed here. To change a name of a port, select Description
from the port menu.
• Lookup Size — Enter the estimated number of lookup records to optimize
memory allocation and lookup performance (this option is described more
detail in “DB Lookup component” on page 101).
• Lookup Empty / Null — Empty and Null are normally handled as
“unknown” keys, thus returning the lookup default value. If Empty or Null
values are valid keys for your lookup, you can enforce looking up the
values for these keys by activating the appropriate options.