|Oracle8i interMedia Text Migration
Release 2 (8.1.6)
Part Number A77061-01
Migrating Your Application, 3 of 4
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:
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.
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 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.
Manual index migration might be useful if you decide to re-design your application using new features in 8.1.
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.
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 Where there is a 2.X indexing feature or object that is obsolete in 8.1, the migration script issues a warning as a comment.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.
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.
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.
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.
For more information about migrating LONG and LONG RAW columns, see Oracle8i Migration.