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 Oracle Forms, programmatically
Refer to Built-in
GET BLOCK PROPERTY
SET BLOCK PROPERTY
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, Oracle Forms 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.