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Migrating and upgrading
You can upgrade to the 14.10 release of HCL Informix® or migrate from other database servers to Informix. Upgrading is an in-place migration method that uses your existing hardware and operating system software. Some changes to the Informix database server can affect upgrading from a previous release.
Migrating Informix® database systems
The Informix® Migration Guide describes how to move data manually between databases, servers, and computers.
Data migration utilities
The LOAD and UNLOAD statements
You can use the SQL LOAD and UNLOAD statements to move data. The LOAD statement is moderately fast and easy to use, but it only accepts specified data formats. You usually use the LOAD statement with data that is prepared with an UNLOAD statement.
Load and unload statements for nondefault locales and the GL_DATETIME and USE_DTENV environment variables
In nondefault locales, operations that load or unload DATETIME or INTERVAL values can be sensitive to the settings of the GL_DATETIME, DBTIME, and USE_DTENV environment variables.

Migrating and upgrading
You can upgrade to the 14.10 release of HCL Informix® or migrate from other database servers to Informix. Upgrading is an in-place migration method that uses your existing hardware and operating system software. Some changes to the Informix database server can affect upgrading from a previous release.
- Migrating Informix® database systems
  The Informix® Migration Guide describes how to move data manually between databases, servers, and computers.
  - Overview of migration
  - Migration to and reversion from 14.10
  - Migration of data between database servers
  - Data migration utilities
    - External tables
      External tables are a fast and versatile method for moving data between database servers. External tables are the fastest method for loading data into a RAW table with no indexes.
    - The dbexport and dbimport utilities
      The dbexport and dbimport utilities import and export a database and its schema to disk or tape.
    - The dbload utility
      The dbload utility loads data into databases or tables that Informix® products created. It transfers data from one or more text files into one or more existing tables.
    - The dbschema utility
      The dbschema utility displays the SQL statements (the schema) that are necessary to replicate database objects.
    - The LOAD and UNLOAD statements
      You can use the SQL LOAD and UNLOAD statements to move data. The LOAD statement is moderately fast and easy to use, but it only accepts specified data formats. You usually use the LOAD statement with data that is prepared with an UNLOAD statement.
      - Syntax of the UNLOAD statement
        The UNLOAD statement in DB-Access unloads selected rows from a table into a text file.
      - Syntax of the LOAD statement
        The LOAD statement in DB-Access appends rows to an existing table of a database.
      - Load and unload statements for locales that support multibyte code sets
        For locales that support multibyte code sets, be sure that the declared size (in bytes) of any column that receives character data is large enough to store the entire data string.
      - Load and unload statements for nondefault locales and the GL_DATETIME and USE_DTENV environment variables
        In nondefault locales, operations that load or unload DATETIME or INTERVAL values can be sensitive to the settings of the GL_DATETIME, DBTIME, and USE_DTENV environment variables.
    - The onunload and onload utilities
      The onunload and onload utilities provide the fastest way to move data between computers that use the same database server on the same platform.
    - The onmode utility reversion option
      You use the -b option of the onmode utility to revert to the older database server from which you converted.
    - The onrestorept utility
      You can use the onrestorept utility to restore the database server back to the state that it was in just before the start of the failed upgrade.

Load and unload operations for nondefault locales and GL_DATETIME or DBTIME environment variables

In nondefault locales, operations that load or unload DATETIME or INTERVAL values can be sensitive to the settings of the GL_DATETIME, DBTIME, and USE_DTENV environment variables.

If the database uses a nondefault locale and the GL_DATETIME or DBTIME environment variable has a nondefault setting, you must set the USE_DTENV environment variable to the value of 1 before you can process localized DATETIME or INTERVAL values correctly

with the LOAD or UNLOAD statements of DB-Access,
or with the dbimport or dbexport utilities,
or in DML operations on objects that the CREATE EXTERNAL TABLE statement defined.