Migrating Your Application, 3 of 4

Migration Plan

Migration assumes you have ConText 2.X installed and are running a ConText application. The goal of migration is to move your ConText 2.X/Oracle 8.0 production application to a working version of the same application in a interMedia Text 8.1/Oracle8i environment.

Migration of a ConText application is not a mechanical process as is a migration from an Oracle7 database to an Oracle8 database. This is because ConText 2.X applications cannot be run in a interMedia Text 8.1 environment.

A migration to interMedia Text 8.1 involves the general plan of:

Migrating Your Index

The migration of a pre-8.1 index involves duplicating the indexing features of the old environment in the new 8.1 environment.

The way you characterize an index in pre-8.1 is similar to 8.1 in that you must create preferences. However, attaching preferences to an index is different in that policies do not exist in 8.1. In 8.1, you name your custom preferences directly in the CREATE INDEX statement.

Note:
Creating your own preferences in 8.1 is necessary only when you require non-default index preferences.
For more information about the characteristics of a default index, see the first chapter in the Oracle8i interMedia Text Reference

Most system-supplied objects you use to create index preferences have been renamed, while others have been made obsolete. Migrating your pre-8.1 index thus involves knowing which system-supplied objects have changed or have been made obsolete.

You can migrate your index preferences and index by using one or both of the following methods:

Manual Index Migration

Manual index migration involves re-creating your pre-8.1 preferences with 8.1 preferences by rewriting your index creation scripts. Your create new preferences with the renamed or new index objects in 8.1, and decide how to migrate preferences based on obsolete objects.

See Also:
For more information about replaced, obsolete, and changed index objects, see "Preference Objects" in Chapter 4.
For more information about how to create preferences and indexes with the new syntax, see Chapter 5, "Indexing".

Manual index migration might be useful if you decide to re-design your application using new features in 8.1.

Index Migration Scripts

To help with migrating a pre-8.1 index to 8.1 index, you can use the migration scripts supplied with the 8.1 installation. You run these scripts in the pre-8.1 environment to create migrate.sql, and then you run migrate.sql in your new 8.1 environment.

The migrate.sql script, written in interMedia Text 8.1 code, attempts to replicate your pre-8.1 index preferences and index in your interMedia Text 8.1 environment. Where there is a 2.X indexing feature or object that is obsolete in 8.1, the migration script issues a warning as a comment. You must make a decision on how to migrate the feature and edit the migration script accordingly.

See Also:
For more information about when you use the migration scripts, see "Migration Steps" in this chapter.
For more information about using the migration scripts, see "Using the Index Migration Scripts" in Chapter 4.

Migrating Your Application Code

To migrate a ConText pre-8.1 application to an iMT application, you must completely re-rewrite your application using 8.1 code. This is because pre-8.1 applications are not forward compatible.

In addition to the code that creates indexes, application code requiring migration includes all code that issues queries and presents documents to users.

The new code is a result of text searching and indexing integration with the Oracle server. For example, the Text index is now a domain index, and as such, you index and query with standard SQL. In addition, there are new PL/SQL procedures that create output for document presentation.

Recreating your application code involves creating a test environment as part of your migration process.

See Also:
For more information about creating a test environment, see "Migration Steps" in this chapter.
For more information about migrating queries, see Chapter 6, "Querying".
For more information about new solutions for document presentation, see Chapter 7, "Document Presentation".

Migrating Your Data: Upgrading to Oracle8i

Migration of data is the transfer of your pre-8.1 data to your 8.1 database. This is also known as upgrading an Oracle8 database to an Oraclel8i database. You do this after installing interMedia Text.

You can migrate your data manually using export/import, or you can use the Oracle Data Migration Assistant, which is started automatically after installing interMedia Text with the Oracle Universal Installer.

See Also:
For more information about upgrading to Oracle8i, see Oracle8i Migration.
For more information about when you migrate your data, see "Migration Steps" in this chapter.

Long Columns

If your pre-8.1 application uses LONG and LONG RAW text columns, you might also consider migrating these columns to LOBs as part of your data migration process.

See Also:
For more information about migrating LONG and LONG RAW columns, see Oracle8i Migration.