IBM 000-8697 ユーザーズマニュアル

IBM Informix OnLine Database Server Administrator’s Guide

The user process type flags occupy the fourth position of each entry in the
tbstat -u

 display, users section. These flags provide the following

information:

The database server process, which can also be referred to as the database
engine process, manages all access to the database. The database server process
exists to service the needs of the application development tool. The two work
in a partnership. The application sends a request for data to the database
server. The server process executes the database query, acquires the
requested information, and sends the results back to the application devel-
opment tool process.

If OnLine is initialized, the tool process forks itself and then performs the

UNIX

execv()

 function call. The database server process that is spawned is

specified by the

SQLEXEC

environment variable. If

SQLEXEC

is not specified,

an OnLine database server process is spawned by default.

OnLine system architecture maintains a one-to-one correspondence between
application processes and database server processes. The application process
is the parent process; the database server process is the child process. The
OnLine database server process is $

.

In the OnLine system, many server processes coexist, any one or all of which
might be active at any time. For the processes that are not active, their status
can be either “ready-to-run,” awaiting CPU resources, or suspended,
awaiting the completion of some other activity before they can be executed.
Processes that are suspended and waiting for some external event are said to
be sleeping.

C

The user process is dead and waiting for proper clean-up. (Refer to

.)

D

The user process is either tbinit or tbundo. (Refer to

F

The user process is a page-cleaner daemon, tbpgcl. (Refer to

.)

M

The user process is a

DB-M

onitor process, tbmonitor.