Informix is one of the easiest databases to back up and recover. Although it is a highly complex, very advanced relational database, it has the least complex recovery of all three database products covered in this book. Informix also was the first among the three products to come out with a live, multilevel backup and restore program. tbtape , as it was called in the early days, was simple enough to understand and use, yet smart enough to handle the job. (The complete documentation set for tbtape was only 14 pages.)
The large number of utilities available to back up Informix databases can be quite confusing, but each is actually made for a separate application. ontape (as tbtape is now called) is Informix’s oldest physical backup utility and is used primarily in environments without a storage manager. onbar is Informix’s newest physical backup utility and is designed only for environments with a storage manager. onunload is a logical backup utility, and onarchive is deprecated and should not be used for new backup systems.
This chapter covers the three basic ways to back up and recover an Informix database:
Physical backups without a storage manager, using ontape
Physical backups with a storage manager, using onbar
Logical backups, using onunload
This chapter also makes recommendations on how to increase the data integrity of your Informix instance, as well as how to recover the instance when necessary.
Let’s begin ...