Skip to Main Content
IBM Data and AI Ideas Portal for Customers

This portal is to open public enhancement requests against products and services offered by the IBM Data & AI organization. To view all of your ideas submitted to IBM, create and manage groups of Ideas, or create an idea explicitly set to be either visible by all (public) or visible only to you and IBM (private), use the IBM Unified Ideas Portal (

Shape the future of IBM!

We invite you to shape the future of IBM, including product roadmaps, by submitting ideas that matter to you the most. Here's how it works:

Search existing ideas

Start by searching and reviewing ideas and requests to enhance a product or service. Take a look at ideas others have posted, and add a comment, vote, or subscribe to updates on them if they matter to you. If you can't find what you are looking for,

Post your ideas

Post ideas and requests to enhance a product or service. Take a look at ideas others have posted and upvote them if they matter to you,

  1. Post an idea

  2. Upvote ideas that matter most to you

  3. Get feedback from the IBM team to refine your idea

Specific links you will want to bookmark for future use

Welcome to the IBM Ideas Portal ( - Use this site to find out additional information and details about the IBM Ideas process and statuses.

IBM Unified Ideas Portal ( - Use this site to view all of your ideas, create new ideas for any IBM product, or search for ideas across all of IBM. - Use this email to suggest enhancements to the Ideas process or request help from IBM for submitting your Ideas.

IBM Employees should enter Ideas at

Status Under review
Workspace Db2
Created by Guest
Created on Dec 12, 2023

Parameter 'PCTFREE FOR UPDATE' in Db2 LUW similar to Db2 z/OS

in Db2 z/OS there is a 'PCTFREE FOR UPDATE' parameter. We will need a similar parameter for Db2 LUW.


Our datawarehouse application 'IDH' uses many Bi-Temporal tables.  An update of any row in the source system will lead to the logical termination of the old row (lowering the upper interval limit of business-time to the current date => UPDATE) and INSERT of a new row with current values.

We assume, that the new inserted DATE,  when performing an UPDATE of the row, will make the new value  a bit longer (maybe because the new date cannot be compressed as well as before: usually = 9999-12-30, identical for many rows).

The defined PCTFREE will now be used up quickly, by the many INSERTS taking place, implicitly caused by the UPDATES causing overflows.

 With an additional option 'PCTFREE FOR UPDATE' there would be the possibility to reserve a part of free space, to avoid overflows.


The docu for 'CREATE TABLE' statement says: 

PCTFREE integer
Specifies the percentage of each page that is to be left as free space. The first row on each page is added without restriction. When additional rows are added to a page, at least integer percent of the page is left as free space. The value of integer can range from 0 to 99. A PCTFREE value of -1 in the system catalog (SYSCAT.TABLES) is interpreted as the default value. The default PCTFREE value for a table page is 0.

The docu for SYSCAT.TABLES states: 
PCTFREE SMALLINT Percentage of each page to be reserved for future inserts.


Needed By Quarter