User`s guide

Source components
84 Sybase IQ ETL 4.1
3 Select an attribute with values that increase whenever data is changed or
added to the source, such as an auto incremental ID or a modification date.
It is not required to have this attribute indexed on the database schema
level; however, for performance reasons Sybase recommends that you
create an index.
4 Enter a Query for the incremental load.
The selection criteria in the
WHERE clause needs to be qualified using the
predefined variable LoadIndex. Enclose the LoadIndex with square brackets,
because it is evaluated before the query is sent to the database, for example:
SELECT * FROM SALES
WHERE SA_DELIVERYDATE > '[LoadIndex]'
ORDER BY SA_DELIVERYDATE
Note Quote characters differ between database systems. On Microsoft Access
databases, use # for datetime values.
Resetting the Ascending Index Value
You cannot directly manipulate the persistent value of the Load Index in the
Repository, but you can reset the value to the one stored in the Load Index
Value property.
❖ To reset the value of the persistent Load Index value
1 Select the project in the Navigator section.
2 Right-click and select Reset Execution Properties.
The optional properties are:
• Load Index Value - The maximum value of the Ascending Index attribute
is automatically used and stored when executing a Sybase IQ ETL
Development job or schedule. The Load Index Value is used to simulate
the project with the specific value provided by the user, for example:
'2005-01-19'
100
• Read Block Size — The Read Block Size defines the number of records
retrieved by the component within in a single simulation step.
• Pre-processing SQL — defines one or more SQL statements to be
executed during initialization of the component.