2-104 IBM Informix OnLine Database Server Administrator’s Guide
tblspace Tblspace
Ifnewly 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.
Ifan additional chunk free-list page is needed to accommodate new entries,
anew chunk free-list page is created in one of the free pages in the chunk. The
chunkfree-list pages are chained in a linked list. Each free-list page contains
entriesthat 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
Inthe 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
collectionof pages that describe the location and structure of all tblspaces in
this dbspace. Figure2-18 illustrates the location of the tblspace tblspace.
Chunk Offset Number of Free Pages
14 28
123 36
208 52
Figure2-18
The tblspace
tblspace appears in
every dbspace,
following the
reserved pages and
the chunk free-list
page.
Tblspace tblspace
Chunk
Reservedpages
Chunk free-list page
Free pages