postgresql/contrib/oracle/README.ora2pg
Bruce Momjian 2e2d17ed51 Here the latest version and first working release of Ora2Pg a tool to export
Oracle database to PostgreSQL.

    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. You can dump only a
    particular schema from the Oracle database.

    Functions, procedures and triggers with SQL or PLSQL 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.

I will add more precision in type NUMBER conversion based on length to match
as closest as possible all rich PostgreSQL numerics type. But it seems not to be

urgent as it seems that Oracle DBAs only create number with length 22 (default)
Space seems not to be their problem...

Gilles DAROLD
2001-06-23 02:56:23 +00:00

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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