INFORMIX SERVER / 5725A3900 / B70 - IDS 11.70

When the onconfig parameter MAX_FILL_DATA_PAGES is set to one
pages within tables using variable length row sizes are marked
full when the free space remaining on the page is less than the
lower of these conditions :
- 10% of the maximum page free space
- the average size of rows on the page

If the average row size on the page is less than 10% of the
maximum page free space then the page will not be considered
full even when more than 90% of available space is used.

A problem may arise when the average row size is more than 10%
of the maximum page free space and the actual page free space is
between the 10% value and the average row size. An attempt to
insert a row with size greater than the actual free space on the
page will fail but the page will not be marked as full. If there
are many such rows to be inserted and having similar sizes then
the same pages will be selected over and over again. Such
behaviour may lead to the start of checkpoint processing being
delayed for extended periods of time.

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* USERS AFFECTED:                                              *
* Users of IDS 11.70.xC9 and earlier versions.                 *
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* PROBLEM DESCRIPTION:                                         *
* With variable row length and MAX_FILL_DATA_PAGES pages might *
* forever offer room that never satisfies any new row,         *
* potentially causing long checkpoint blocks.                  *
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* RECOMMENDATION:                                              *
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Set the onconfig parameter to 0 MAX_FILL_DATA_PAGES and restart
the engine. Then run 'oncheck -cD : -y' for each
table in each database that uses variable length row sizes. For
each page that does not have sufficient space for a row of
maximum size the bitmap will be updated to mark the page as
full.

not known / see Local fix

Date  - problem reported    :
Date  - problem closed      :
Date  - last modified       :

19.11.2018
08.10.2019
31.08.2020