ODBC Server Reference Manual

HP NonStop ODBC Server Mapping Tables
HP NonStop ODBC Server Reference Manual—429151-002
8-29
ZNSSCFG (For System Configuration Values)
Storage of System Information
ZNSSCFG contains two special rows that represent data that pertains to the entire
collection of data stored on ZNSSCFG. These are the rows that contain the values
“LAST_UPDATE_SYSTEM_CONFIG” and “CHECK_INTERVAL_SECONDS” in the
ITEM column. The LAST_UPDATE_SYSTEM_CONFIG row describes the last time the
system configuration was updated and the CHECK_INTERVAL_SECONDS row tells
for how long the update is effective.
The term “default” is dynamic within a system installation. When a process begins, the
programs retrieve the values from the ZNSSCFG table. These values are in effect for a
time specified in the VALUE column for the ITEM that has a value of
“CHECK_INTERVAL_SECS” in the ZNSSCFG table.
Valid values are as follows:
•
“–1” means no polling takes place to determine whether the value is still in effect.
•
“0” means the value of the column or attribute is in effect for the length of the
process.
•
A number other than “–1” or “0” represents the number of seconds the value for the
column or attribute is in effect. Usually the number is fairly high, such as “3000.”
Duration of Default Values
The time that a default value is in effect is measured from the time the
CHECK_INTERVAL_SECONDS value was last updated.
The NOS, SCS, and NOSUTIL processes use the CHECK_INTERVAL_SECS value in
different ways:
•
The NOS process checks the value of CHECK_INTERVAL_SECS at the beginning
of a session and does not check it through the remainder of the session when it
ends with a disconnect.
•
Once an SCS process begins, SCS may check the value for
CHECK_INTERVAL_SECS more than once during a session. The SCS process
uses the NOSUTIL process to perform this check.
•
NOSUTIL checks the value in CHECK_INTERVAL_SECS with every message it
receives.
If the value in CHECK_INTERVAL_SECONDS shows that the value for the column or
attribute is no longer in effect, the process (NOS, SCS, or NOSUTIL) determines a
course of action.
When No Default Values Are Found
The NOSUTIL, NOS and SCS processes have some default values built into their
programs. Whenever a NOSUTIL, NOS, or SCS process cannot find a default value on
ZNSSCFG, the process continues by using the default values built into their programs.