Oracle Forms Developer – Form Builder Reference, Volume 1

Update Changed Columns Only property
Description
When queried records have been marked as updates, specifies that only columns whose values were
actually changed should be included in the SQL UPDATE statement that is sent to the database during a
COMMIT. By default, Update Changed Columns Only is set to No, and all columns are included in the
UPDATE statement.
Applies to block
Set Form Builder, programmatically
Refer to Built-in
• GET_BLOCK_PROPERTY
• SET_BLOCK_PROPERTY
Default :
No
Required/Optional optional
Usage Notes
• If the DML Array Size property is set to a value greater than 1, this Update Changed Columns Only
property will be ignored at runtime. That is, a DML Array Size greater than 1 causes all columns to
be updated – even if Update Changed Columns Only was set to Yes.
• When Update Changed Columns Only is No, Form Builder can reuse the same SQL statement for
multiple updates, without having to reparse each time. Setting Update Changed Columns Only to
Yes can degrade performance because the UPDATE statement must be reparsed each time. In
general, you should only set Update Changed Columns Only to Yes when you know that operators
will seldom update column values that will take a long time to transfer over the network, such as
LONGs.
• Set Update Changed Columns Only to Yes in the following circumstances:
To save on network traffic, if you know an operator will primarily update only one or two columns.
To avoid re-sending large items that are not updated, such as images or LONGs.
To fire database triggers on changed columns only. For example, if you implement a security scheme
with a database trigger that fires when a column has been updated and writes the userid of the person
performing the update to a table.
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