2
Migrating Your Application

This chapter describes the interMedia Text migration process. The following topics are covered:

Migration Path

This book describes migrating a ConText 2.X application running on an Oracle 8.0 database to a interMedia Text 8.1.5 application running on an Oracle 8i database, version 8.1.5.

Note:
You cannot run ConText 2.X applications on an Oracle8i database.

Oracle8 Users

If you are running ConText 2.X on an Oracle8 database, you must migrate to interMedia Text 8.1.5, which also involves upgrading your Oracle8 database.

See Also:
"Migration Plan" in this chapter.

Oracle7 Users

If you are running ConText 2.X on an Oracle7 database, you must migrate your database to Oracle8i before you can migrate your application to interMedia Text 8.1.

Note:
For more information about migrating an Oracle7 database to an Oracle8i database, refer to the Oracle8i Migration.

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 8.1.5/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 8.1.5 environment.

A migration to interMedia Text 8.1.5 involves the general plan of:

Migrating Your Index

The migration of a pre-8.1.5 index involves duplicating the indexing features of the old environment in the new 8.1.5 environment.

The way you characterize an index in pre-8.1.5 is similar to 8.1.5 in that you must create preferences. However, attaching preferences to an index is different in that policies do not exist in 8.1.5. In 8.1.5, you name your custom preferences directly in the CREATE INDEX statement.

Note:
Creating your own preferences in 8.1.5 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-8.1.5 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-8.1.5 preferences with 8.1.5 preferences by rewriting your index creation scripts. Your create new preferences with the renamed or new index objects in 8.1.5, 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 8.1.5.

Index Migration Scripts

To help with migrating a pre-8.1.5 index to 8.1 index, you can use the migration scripts supplied with the 8.1.5 installation. You run these scripts in the pre-8.1.5 environment to create migrate.sql, and then you run migrate.sql in your new 8.1.5 environment.

The migrate.sql script, written in interMedia Text 8.1.5 code, attempts to replicate your pre-8.1.5 index preferences and index in your interMedia Text 8.1.5 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-8.1.5 application to an iMT application, you must completely re-rewrite your application using 8.1.5 code. This is because pre-8.1.5 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-8.1.5 data to your 8.1.5 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-8.1.5 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.

Migration Steps

This section describes the requirements for migration as well as the steps you must take to migrate your application.

Disk Space Requirements

The migration step assumes that you have enough disk space to create a separate test environment, in addition to your production environment, that contains the following elements:

all or a subset of your production data
new application code

Hardware Considerations

A migration to Oracle8i interMedia Text involves using three Oracle homes:

pre-8.1.5 production Oracle home
test 8.1.5 Oracle home
new production 8.1.5 Oracle home

You might consider creating your test oracle home on a separate machine from your pre-8.1.5 production oracle home. Do this so that your test environment does not compete for resources such as disk space and processing time with your production environment while you recreate your application code.

You must create a new 8.1.5 oracle home to upgrade your database. The upgrade process for Oracle8 to Oracle8i expects this to be on the same machine, but this is not necessary.

Steps

Table 2-1 outlines a possible plan for migrating your pre-8.1.5 application running on Oracle8 to a working 8.1.5 application running on Oracle8i. This plan suggests setting up a test environment next to your production environment, outlining the steps you execute in each environment.

Note:
The following table is a recommended plan. The exact details of a migration plan will differ from site to site depending on how your application is designed.

Table 2-1

Step	Production Environment	Test Environment
1.	Running	Install interMedia Text 8.1.5 and Oracle8i software in an Oracle home separate from your production Oracle home. This test Oracle home is your test environment.
2.	Copy drminst and drmrun from test environment. See "Using the Index Migration Scripts" in Chapter 4.
3.	Run drminst and drmrun scripts to generate migrate.sql. See "Using the Index Migration Scripts" in Chapter 4.
4.	Export all or subset of production data to be used in the test environment.
5.	Running	Start Oracle8i database server.
6.	Running	Import data or subset of production data.
7.	Running	Copy migrate.sql from production environment.
8.	Running	Edit migrate.sql. See "Using the Index Migration Scripts" in Chapter 4.
9.	Running	Migrate your index by running either migrate.sql or your own index creation scripts. See "Migrating Your Index" in this chapter. You now have an interMedia Text 8.1.5 environment with schema and indexes similar to your pre-8.1.5 production environment.
10.	Running	Migrate pre-8.1.5 application code. See "Migrating Your Application Code"in this chapter.
11.	Running	Test application in interMedia Text 8.1.5 environment.
12.	Backup your pre-8.1.5 system.
13.	Drop your indexes and CTXSYS schema.
14.	Install interMedia Text 8.1.5 using the Oracle Universal Installer. In this process, you must create a new Oracle home for your Oracle8i interMedia Text installation. This new Oracle home will soon become your new production Oracle home. This new home is different from the old production Oracle home (which runs on Oracle8) and the test Oracle home. This installation process also creates a new CTXSYS user and the 8.1.5 interMedia Text data dictionary.
15.	Migrate your data (same as upgrading to Oracle8i) using the Oracle Data Migration Assistant. The Oracle Universal Installer starts this assistant automatically after you install interMedia Text. See "Migrating Your Data: Upgrading to Oracle8i" in this chapter.
16.	Copy migrate.sql and other newly created index creation scripts from your test Oracle home.
17.	Run migrate.sql and/or other index creating scripts to recreate index.
18.	Copy new 8.1.5 application code from test oracle home.
19.	Run 8.1.5 application.

2 Migrating Your Application