Ora2Pg - Oracle to PostgreSQL database schema converter

- NAME
- SYNOPSIS
- DESCRIPTION
- ABSTRACT
- REQUIREMENT
- PUBLIC METHODS
  - new HASH_OPTIONS
  - export_sql FILENAME
- PRIVATE METHODS
  - _init HASH_OPTIONS
  - _grants
  - _sequences
  - _triggers
  - _functions
  - _tables
  - _views
  - _get_sql_data
  - _sql_type INTERNAL_TYPE LENGTH
  - _column_info TABLE
  - _primary_key TABLE
  - _unique_key TABLE
  - _foreign_key TABLE
  - _get_users
  - _get_roles
  - _get_all_grants
  - _get_indexes TABLE
  - _get_sequences
  - _get_views
  - _get_triggers
  - _get_functions
  - _table_info
- AUTHOR
- COPYRIGHT
- BUGS
- SEE ALSO

# NAME

Ora2Pg - Oracle to PostgreSQL database schema converter

# SYNOPSIS

            BEGIN {
                    $ENV{ORACLE_HOME} = '/usr/local/oracle/oracle816';
            }

            use strict;

            use Ora2Pg;

            # Init the database connection
            my $dbsrc = 'dbi:Oracle:host=testdb.samse.fr;sid=TEST;port=1521';
            my $dbuser = 'system';
            my $dbpwd = 'manager';

            # Create an instance of the Ora2Pg perl module
            my $schema = new Ora2Pg (
                    datasource => $dbsrc,           # Database DBD datasource
                    user => $dbuser,                # Database user
                    password => $dbpwd,             # Database password
            );

            # Create the POSTGRESQL representation of all objects in the database
            $schema->export_schema("output.sql");

            exit(0);

or if you only want to extract some tables:

            # Create an instance of the Ora2Pg perl module
            my @tables = ('tab1', 'tab2', 'tab3');
            my $schema = new Ora2Pg (
                    datasource => $dbsrc,           # Database DBD datasource
                    user => $dbuser,                # Database user
                    password => $dbpwd,             # Database password
                    tables => \@tables,
            or                                      # Tables to extract
                    tables => [('tab1','tab2')],
                    debug => 1                      # To show somethings when running
            );

or if you only want to extract the 10 first tables:

            # Create an instance of the Ora2Pg perl module
            my $schema = new Ora2Pg (
                    datasource => $dbsrc,           # Database DBD datasource
                    user => $dbuser,                # Database user
                    password => $dbpwd,             # Database password
                    max => 10                       # 10 first tables to extract
            );

or if you only want to extract tables 10 to 20:

            # Create an instance of the Ora2Pg perl module
            my $schema = new Ora2Pg (
                    datasource => $dbsrc,           # Database DBD datasource
                    user => $dbuser,                # Database user
                    password => $dbpwd,             # Database password
                    min => 10,                      # Begin extraction at indice 10
                    max => 20                       # End extraction at indice 20
            );

To choose a particular schema just set the following option to your schema name :

            schema => 'APPS'

To know at which indices table can be found during extraction use the option:

            showtableid => 1

To extract all views set the option type as follow:

            type => 'VIEW'

To extract all grants set the option type as follow:

            type => 'GRANT'

To extract all sequences set the option type as follow:

            type => 'SEQUENCE'

To extract all triggers set the option type as follow:

            type => 'TRIGGER'

To extract all functions set the option type as follow:

            type => 'FUNCTION'

To extract all procedures set the option type as follow:

            type => 'PROCEDURE'

Default is table schema extraction

            type => 'TABLE'

# DESCRIPTION

Ora2Pg is a perl OO module used to export an Oracle database schema to a PostgreSQL compatible schema.

It simply connect to your Oracle database, extract its structure and generate a SQL script that you can load into your PostgreSQL database.

I'm not a Oracle DBA so I don't really know something about its internal structure so you may find some incorrect things. Please tell me what is wrong and what can be better.

It currently dump the database schema (tables, views, sequences, indexes, grants), with primary, unique and foreign keys into PostgreSQL syntax without editing the SQL code generated.

Functions, procedures and triggers PL/SQL code generated must be reviewed to match the PostgreSQL syntax. Some usefull recommandation on porting Oracle to PostgreSQL can be found at http://techdocs.postgresql.org/ under the ``Converting from other Databases to PostgreSQL'' Oracle part. I just notice one thing more is that the `trunc()` function in Oracle is the same for number or date so be carefull when porting to PostgreSQL to use `trunc()` for number and `date_trunc()` for date.

# ABSTRACT

The goal of the Ora2Pg perl module is to cover all part needed to export an Oracle database to a PostgreSQL database without other thing that provide the connection parameters to the Oracle database.

Features must include:

            - Database schema export (tables, views, sequences, indexes),
              with unique, primary and foreign key.
            - Grants/privileges export by user and group.
            - Table selection (by name and max table) export.
            - Predefined functions/triggers/procedures export.
            - Sql query converter (todo)
            - Data export (todo)

My knowledge regarding database is really poor especially for Oracle so contribution is welcome.

# REQUIREMENT

You just need the DBI and DBD::Oracle perl module to be installed

# PUBLIC METHODS

## new HASH_OPTIONS

Creates a new Ora2Pg object.

Supported options are:

            - datasource    : DBD datasource (required)
            - user          : DBD user (optional with public access)
            - password      : DBD password (optional with public access)
            - schema        : Oracle internal schema to extract
            - type          : Type of data to extract, can be TABLE,VIEW,GRANT,SEQUENCE,TRIGGER,FUNCTION,PROCEDURE
            - debug         : Print the current state of the parsing
            - tables        : Extract only the given tables (arrayref)
            - showtableid   : Display only the table indice during extraction
            - min           : Indice to begin extraction. Default to 0
            - max           : Indice to end extraction. Default to 0 mean no limits

Attempt that this list should grow a little more because all initialization is done by this way.

## export_sql FILENAME

Print SQL conversion output to a filename or to STDOUT if no file is given.

# PRIVATE METHODS

## _init HASH_OPTIONS

Initialize a Ora2Pg object instance with a connexion to the Oracle database.

## _grants

This function is used to retrieve all privilege information.

It extract all Oracle's ROLES to convert them as Postgres groups and search all users associated to these roles.

Set the main hash $self->{groups}. Set the main hash $self->{grantss}.

## _sequences

This function is used to retrieve all sequences information.

Set the main hash $self->{sequences}.

## _triggers

This function is used to retrieve all triggers information.

Set the main hash $self->{triggers}.

## _functions

This function is used to retrieve all functions information.

Set the main hash $self->{functions}.

## _tables

This function is used to retrieve all table information.

Set the main hash of the database structure $self->{tables}. Keys are the names of all tables retrieved from the current database. Each table information compose an array associated to the table_info key as array reference. In other way:

        $self->{tables}{$class_name}{table_info} = [(OWNER,TYPE)];

DBI TYPE can be TABLE, VIEW, SYSTEM TABLE, GLOBAL TEMPORARY, LOCAL TEMPORARY, ALIAS, SYNONYM or a data source specific type identifier. This only extract TABLE type.

It also get the following informations in the DBI object to affect the main hash of the database structure :

        $self->{tables}{$class_name}{field_name} = $sth->{NAME};
        $self->{tables}{$class_name}{field_type} = $sth->{TYPE};

It also call these other private subroutine to affect the main hash of the database structure :

        @{$self->{tables}{$class_name}{column_info}} = $self->_column_info($class_name);
        @{$self->{tables}{$class_name}{primary_key}} = $self->_primary_key($class_name);
        @{$self->{tables}{$class_name}{unique_key}}  = $self->_unique_key($class_name);
        @{$self->{tables}{$class_name}{foreign_key}} = $self->_foreign_key($class_name);

## _views

This function is used to retrieve all views information.

Set the main hash of the views definition $self->{views}. Keys are the names of all views retrieved from the current database values are the text definition of the views.

It then set the main hash as follow:

        # Definition of the view
        $self->{views}{$table}{text} = $view_infos{$table};

## _get_sql_data

Returns a string containing the entire SQL Schema definition compatible with PostgreSQL

## _sql_type INTERNAL_TYPE LENGTH

This function return the PostgreSQL datatype corresponding to the Oracle internal type.

## _column_info TABLE

This function implements a Oracle-native column information.

Return a list of array reference containing the following informations for each column the given a table

[( column name, column type, column length, nullable column, default value )]

## _primary_key TABLE

This function implements a Oracle-native primary key column information.

Return a list of all column name defined as primary key for the given table.

## _unique_key TABLE

This function implements a Oracle-native unique key column information.

Return a list of all column name defined as unique key for the given table.

## _foreign_key TABLE

This function implements a Oracle-native foreign key reference information.

Return a list of hash of hash of array reference. Ouuf! Nothing very difficult. The first hash is composed of all foreign key name. The second hash just have two key known as 'local' and remote' corresponding to the local table where the foreign key is defined and the remote table where the key refer.

The foreign key name is composed as follow:

        'local_table_name->remote_table_name'

Foreign key data consist in two array representing at the same indice the local field and the remote field where the first one refer to the second. Just like this:

        @{$link{$fkey_name}{local}} = @local_columns;
        @{$link{$fkey_name}{remote}} = @remote_columns;

## _get_users

This function implements a Oracle-native users information.

Return a hash of all users as an array.

## _get_roles

This function implements a Oracle-native roles information.

Return a hash of all groups (roles) as an array of associated users.

## _get_all_grants

This function implements a Oracle-native user privilege information.

Return a hash of all tables grants as an array of associated users.

## _get_indexes TABLE

This function implements a Oracle-native indexes information.

Return hash of array containing all unique index and a hash of array of all indexes name which are not primary keys for the given table.

## _get_sequences

This function implements a Oracle-native sequences information.

Return a hash of array of sequence name with MIN_VALUE, MAX_VALUE, INCREMENT and LAST_NUMBER for the given table.

## _get_views

This function implements a Oracle-native views information.

Return a hash of view name with the SQL query it is based on.

## _get_triggers

This function implements a Oracle-native triggers information.

Return an array of refarray of all triggers informations

## _get_functions

This function implements a Oracle-native functions information.

Return a hash of all function name with their PLSQL code

## _table_info

This function retrieve all Oracle-native tables information.

Return a handle to a DB query statement

# AUTHOR

Gilles Darold <gilles@darold.net>

# COPYRIGHT

Copyright (c) 2001 Gilles Darold - All rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

# BUGS

This perl module is in the same state as my knowledge regarding database, it can move and not be compatible with older version so I will do my best to give you official support for Ora2Pg. Your volontee to help construct it and your contribution are welcome.

# SEE ALSO

DBI, DBD::Oracle