In This Chapter

This chapter describes the dbexport and dbimport utilities and how to use them. You can use dbexport and dbimport with the following database servers:

The dbexport utility unloads a database into text files for later import into another database and creates a schema file. The dbimport utility creates and populates a database from text files. You can use the schema file with dbimport to re-create the database schema in another Informix environment. You can edit the schema file to modify the database that dbimport creates. The dbexport and dbimport utilities support Dynamic Server 10.0, 9.40, 9.30, and 9.2x extended data types.

Dates are stored in four-digit years. By default, dbexport exports dates in four-digit year dates unless the environment variable DBDATE is set to "mdy2" or to some other value that specifies abbreviated years. We do not recommend this setting for exporting a database because data imported back into the database depends on either the DBCENTURY environment variable, if set, or the current century if DBCENTURY is not set.

Disable SELECT triggers before exporting a database with dbexport. The dbexport utility executes SELECT statements during export. The SELECT statement triggers can modify the database content.

When you import a database, use the same environment variable settings that were used when the database was created or you might get unexpected results. If any fragmentation expressions, check constraints, triggers, or user-defined routines were created with different settings than you use with dbimport, you cannot reproduce the database accurately with a single import.

If the date context during import is not the same as when these objects were created, you might get explicit errors, or you might not be able to find your data, or a check constraint might not work as expected, and so forth. Many of these problems do not generate errors. The date context for an object includes the date the object was created, the values of the DBCENTURY and DBDATE environment variables, and some other environment variables. To avoid such problems with the date context, use four-digit dates in all cases.

Similar problems might occur with environment variables that specify GLS locales. such as DB_LOCALE, SERVER_LOCALE, and CLIENT_LOCALE. For more information, see the IBM Informix: GLS User's Guide.