postgresql/contrib/oracle/README.ora2pg

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,             # Tables to extract
                    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 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'

    Default is table schema extraction

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 only dump the database schema, with primary, unique and
    foreign keys. I've tried to excluded internal system tables but perhaps
    not enougt, please let me know.

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, with unique, primary and foreign key.
            - Grants/privileges export by user and group.
            - Indexes and unique indexes export.
            - Table or view selection (by name and max table) export.
            - Predefined function/trigger export (todo)
            - Data export (todo)
            - Sql query converter (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)
            - type          : Type of data to extract, can be TABLE (default) or VIEW
            - 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.

PUBLIC METHODS
  _init HASH_OPTIONS

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

  _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}} = &_column_info($self, $class_name);
        @{$self->{tables}{$class_name}{primary_key}} = &_primary_key($self, $class_name);
        @{$self->{tables}{$class_name}{unique_key}}  = &_unique_key($self, $class_name);
        @{$self->{tables}{$class_name}{foreign_key}} = &_foreign_key($self, $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};
        # Grants defined on the views 
        $self->{views}{$table}{grants} = when I find how...

  _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_table_privilege TABLE

    This function implements a Oracle-native table grants information.

    Return a hash of array of all users and their grants on the given table.

  _get_roles

    This function implements a Oracle-native roles/users information.

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

  _get_indexes TABLE

    This function implements a Oracle-native indexes information.

    Return an array of all indexes name which are not primary keys for the
    given table.

    Note: Indexes name must be created like this tablename_fieldname else
    they will not be retrieved or if tablename false in the output
    fieldname.

  _get_sequences TABLE

    This function implements a Oracle-native sequence information.

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

    Not working yet.

  _get_views

    This function implements a Oracle-native views information.

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

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
    the DBI manpage, the DBD::Oracle manpage