IBM 000-8697 OnLine Dbspace Table

2-50 IBM Informix OnLine Database Server Administrator’s Guide
Shared-Memory Internal Tables
■Thenumber of chunk entries (pathnames) that can fit on an OnLine
page
■The operating-system value of maximum number of open files per
process, minus 6
Referto page 2-93for instructions on calculating the number of chunk entries
per OnLine page.
OnLine Dbspace Table
The dbspace table tracks both dbspaces and blobspaces in the OnLine
system.
Thedbspace table information includes the following information about each
dbspace in the OnLine configuration:
■Dbspace number
■Dbspace name and owner
■Dbspace mirror status (if mirrored or not)
■Date and time the dbspace was created
Ifthe space is a blobspace, flags indicate the medium where the blobspace is
located, eithermagnetic or removable.
Themaximum number of entries in the dbspace table is equal to the value of
DBSPACES, the maximum number of dbspaces permitted in OnLine, as
specified in the configuration file.
Each entry in the dbspaces table occupies 46 bytes.
Referto page 3-75for information about monitoring dbspaces using tbstat -d
and tbstat -D.
Themaximum number of dbspaces plus blobspaces that can exist within an
OnLine configuration is the number of chunks that can exist within this
configuration, since each dbspace requires at least one chunk.
Themaximum number of chunks that can exist within a configuration might
be operating-system dependent. Refer topage 2-49 for general information
about the maximum number of chunks or topage 2-93 for specific infor-
mation about calculating the maximum value.