System Architecture 2-97
Reserved Pages
PAGE_PZERO
Thefirst reserved page in the root dbspace is PAGE_PZERO. Below are listed
the PAGE_PZERO fields and definitions. To obtain a listing of the reserved
page, execute the commandtbcheck -pr.
PAGE_CONFIG
The second reserved page in the root dbspace isPAGE_CONFIG. This page
contains either a copy of the configuration file specified by$INFOR-
MIXDIR/etc/$TBCONFIG or, ifTBCONFIG is not set, the file
$INFORMIXDIR/etc/tbconfig,by default. (Refer to page 1-13for a listing of all
configuration file parameters.)
PAGE_CKPT
The third reserved page in the root dbspace isPAGE_1CKPT. The fourth
reserved page,PAGE_2CKPT, is the second page in the pair.
Thetbinit daemon uses the checkpoint and logical log file information for
checkpoint processing. The date and time of the last checkpoint, available
from the Force-Ckpt menu, is obtained from this reserved page. (Refer to
page 2-72 for a complete explanation of the checkpoint procedure.)
Field Name Description
Identity IBMInformix OnLine copyright
Database system state Unused
Database system flags Unused
Page size Page size for this machine, in bytes
Date/time created Date and time of disk space initialization
Version number Unused
Last modified timestamp Unused (although a 1 appears)