System Architecture 2-87

Structure of the Root Dbspace

Structure of the Root Dbspace
TheOnLine configuration file contains the location of the initial chunk of the
rootdbspace. If the root dbspace is mirrored, the mirror chunk location is also
specified in the configuration file.
As part of disk space initialization, thetbinit daemon initializes the
following structures in the initial chunk of the root dbspace:
Twelve reserved pages (page2-95)
The first chunk free-list page (page2-103)
The tblspace tblspace (page 2-104)
The database tblspace (page 2-107)
The physical log (page 2-151)
The logical log files (page 2-153)
Unused pages
Figure2-12 illustrates the structures residing in the root dbspace following
disk space initialization. Each of these structures is described in the
paragraphs that follow. To see that your root dbspace follows this organi-
zation,execute the command tbcheck -pe, which produces a dbspace usage
report,by chunk. (The database tblspace does not appear in the tbcheck -pe
output.)