IBM 000-8697 Things to Avoid

3-116 IBM Informix OnLine Database Server Administrator’s Guide
Things to Avoid
From the Command Line
1. To change the value of CLEANERS from the command line, use an
editor to edit the file specified by$ INFORMIXDIR/etc/$TBCONFIG.
2. Change the value of CLEANERS. Reinitialize shared memory (take
OnLine offline and then to quiescent mode) for the change to take
effect.
Things to Avoid
Here are some ideas that might sound good in theory, but have unexpected
consequencesthat could adversely affect your OnLine performance. Below is
a list of things to avoid:
■Never kill an OnLine database server process during database
activity.Checkthat the server process is not holding a latch and is not
ina critical section. Use tbmode -z to end a database server process.
Refer topage 2-32.
■Avoid transactions that span a significant percentage of available
logical log space.
■Do not define your archive tape device (TAPEDEV) as a named pipe.
■Donot rely on dbexport (a utility that creates a copy of your database
for migrating) as an alternative to creating routine archives.
■Do not run utilities that send output to tape in background mode
(using the & operator).
■Donot switch the logical log tape device between a tape device and
/dev/null while the logical log files are in use.