postgres/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
                    {
                            PrintError => 0,
                            RaiseError => 1,
                            AutoCommit => 0
                    }
            );

            # 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 Oracle schema to export just set the following
    option to your schema name:

            schema => 'APPS'

    This schema definition can also be needed when you want to export data.
    If export failed and complain that the table doesn't exists use this to
    prefix the table name by the schema name.

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

            showtableid => 1

    To extract all views set the type option as follow:

            type => 'VIEW'

    To extract all grants set the type option as follow:

            type => 'GRANT'

    To extract all sequences set the type option as follow:

            type => 'SEQUENCE'

    To extract all triggers set the type option as follow:

            type => 'TRIGGER'

    To extract all functions set the type option as follow:

            type => 'FUNCTION'

    To extract all procedures set the type option as follow:

            type => 'PROCEDURE'

    To extract all packages and body set the type option as follow:

            type => 'PACKAGE'

    Default is table extraction

            type => 'TABLE'

    To extract all data from table extraction as INSERT statement use:

            type => 'DATA'

    To extract all data from table extraction as COPY statement use:

            type => 'COPY'

    and data_limit => n to specify the max tuples to return. If you set this
    options to 0 or nothing, no limitation are used. Additional option
    'table', 'min' and 'max' can also be used.

    When use of COPY or DATA you can export data by calling method:

    $schema->export_data("output.sql");

    Data are dumped to the given filename or to STDOUT with no argument. You
    can also send these data directly to a PostgreSQL backend using the
    following method:

    $schema->send_to_pgdb($destdatasrc,$destuser,$destpasswd);

    In this case you must call export_data() without argument after the call
    to method send_to_pgdb().

    If you set type to COPY and you want to dump data directly to a PG
    database, you must call method send_to_pgdb but data will not be sent
    via DBD::Pg but they will be load to the database using the psql
    command. Calling this method is istill required to be able to extract
    database name, hostname and port information. Edit the $PSQL variable to
    match the path of your psql command (nothing to edit if psql is in your
    path).

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.

    It now can dump Oracle data into PostgreSQL DB as online process. You
    can choose what columns can be exported for each table.

    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/packages export.
            - Data export.
            - Sql query converter (todo)

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

REQUIREMENT
    You just need the DBI, DBD::Pg 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,DATA,COPY,PACKAGE
            - 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
            - data_limit    : Number max of tuples to return during data extraction (default 10)

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

  export_data FILENAME

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

    Must be used only if type option is set to DATA or COPY =cut

    sub export_data { my ($self, $outfile) = @_;

            $self->_get_sql_data($outfile);
    }

  export_sql FILENAME

    Print SQL conversion output to a filename or simply return these data if
    no file is given.

  send_to_pgdb DEST_DATASRC DEST_USER DEST_PASSWD

    Open a DB handle to a PostgreSQL database

  modify_struct TABLE_NAME ARRAYOF_FIELDNAME

    Modify a table structure during export. Only given fieldname will be
    exported.

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}.

  _packages

    This function is used to retrieve all packages information.

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

  _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

  _get_data TABLE

    This function implements a Oracle-native data extraction.

    Return a list of array reference containing the data

  _sql_type INTERNAL_TYPE LENGTH PRECISION SCALE

    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.

  _alias_info

    This function implements a Oracle-native column information.

    Return a list of array reference containing the following informations
    for each alias of the given view

    [( column name, column id )]

  _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

  _get_packages

    This function implements a Oracle-native packages 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, the DBD::Pg manpage

ACKNOWLEDGEMENTS
    Thanks to Jason Servetar who decided me to implement data extraction.