2-30 IBM Informix OnLine Database Server Administrator’s Guide

OnLine Database Server Process

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:
OnLine Database Server Process
The database server process, which can also be referred to as thedatabase
engineprocess, manages all access to the database. The database server process
existsto 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
specifiedby the SQLEXEC environment variable. If SQLEXEC is not specified,
an OnLine database server process is spawned by default.
OnLinesystem architecture maintains a one-to-one correspondence between
applicationprocesses and database server processes. The application process
is the parentprocess; the database server process is the child process. The
OnLine database server process is$INFORMIXDIR/lib/sqlturbo.
Inthe OnLine system, many server processes coexist, any one or all of which
mightbe 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.
Processesthat are suspended and waiting for some external event are said to
besleeping.
CTheuser process is dead and waiting for proper clean-up. (Refer to
page 2-33.)
DThe user process is eithertbinit or tbundo. (Refer topage 2-33.)
FThe user process is a page-cleanerdaemon, tbpgcl. (Refer to
page 2-33.)
MThe user process is aDB-Monitor process, tbmonitor.