The DBPATH environment variable specifies the search path that Informix will use to locate a database.
Because Informix Standard Engine stores databases as <database name>.dbs directories on the filesystem, it is necessary to specify to the database engine the location in which it should try to locate these files.
The search for database is done first in the directory of database server specified in the statement. If no database is specified, the default database server that was specified by the INFORMIXSERVER environment variable is used.
If the database is not located during the initial search, and if DBPATH is set, the database servers and directories in DBPATH are searched for in the specified database. These entries are searched in the same order which they are listed in the DBPATH setting.
For users of Informix SE, this variable can also specify the paths for the physical database files. If the pathname specifies a directory name but not a database server name, the directory is sought on the computer that runs the default database server that the INFORMIXSERVER specifies.