IBM 000-8697 User Manual

Page of 702
2-104
IBM Informix OnLine Database Server Administrator’s Guide
tblspace Tblspace
If newly freed space is contiguous with existing free space, only the length of
the existing entry is changed; otherwise, a new entry is created.
Illustrated here is a sample listing from a chunk free-list page.
If an additional chunk free-list page is needed to accommodate new entries,
a new chunk free-list page is created in one of the free pages in the chunk. The
chunk free-list pages are chained in a linked list. Each free-list page contains
entries that describe all free space starting with the next page and continuing
to the next chunk free-list page or to the end of the chunk.
tblspace Tblspace
In the initial chunk of every dbspace, the page that follows the chunk free-list
page is the first page of the tblspace tblspace. The tblspace tblspace is a
collection of pages that describe the location and structure of all tblspaces in
this dbspace.
 illustrates the location of the tblspace tblspace.
Chunk Offset
Number of Free Pages
14
28
123
36
208
52
Figure 2-18
The tblspace
tblspace appears in
every dbspace,
following the
reserved pages and
the chunk free-list
page.
Tblspace tblspace
Chunk
Reserved pages
Chunk free-list page
Free pages