2-132 IBM Informix OnLine Database Server Administrator’s Guide
Data Pages and Data Row Storage
Figure2-31
An updated row
thatis longer than a
full page can be
stored as a leading
segment, with a
forwardpointer to a
big-remainder
page. If the leading
segment does not
fit in the current
page location, the
entire data row is
moved and only a
forward pointer is
left in the current
row position.
Whole-page segment of the modified row
Modified row size is longer than a page
Header
Original row size and location
Header
Forward pointer (rowid) to new location
1. Data storage before data is modified
3. Data storage after data is modified
Leading segment of row
Header
2. Data is modified