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,
            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
    the DBI manpage, the DBD::Oracle manpage