This document provides information about PostgreSQL and Command Prompt Inc. It discusses that Command Prompt offers professional services for migrating from Oracle to PostgreSQL. It then covers aspects of PostgreSQL like its licensing, large international community, low costs, mature codebase, enterprise features, and technical capabilities like its SQL implementation, replication, foreign data wrappers and user-defined functions. It also notes tools that can help ease migration from Oracle and some differences from Oracle.

1. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Postgres for Oracle people

2. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Professional Services
For professional services or support contracts for
all of your Oracle to PostgreSQL or Open Source
needs, please contact CMD at:
● +1.503.667.4564
● sales@commandprompt.com
● https://www.commandprompt.com/

3. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Who Am I
● @jdatcmd/@linuxhiker
● jd@commandprompt.com
● Lead Architect – Command Prompt, Inc.
● Director & Founder – PgUS (501c3)

4. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Why PostgreSQL
● Licensing
● Community
● Business
● Tech!

5. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Licensing
● BSD licensed
● Can I?

6. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Can I?
● Fork it?: Yes
● Close it?: Yes
● Modify it?: Yes
● Not share it?: Yes
● Throw it away?: Yes
● Sue you?: Nein!

7. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Community
● Large International Community:
– Postgresql.org
● Postgresql.us
● Postgresql.eu
– Germany, Nordic, France, Italy...
● Postgresql.jp
● Postgres.cn

8. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Business
● Costs
● Support

9. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Costs
● PostgreSQL is 100% free.
– Zero cost to download
– Zero cost to install
– Zero cost to support (assuming expertise)

10. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Established companies
(Support)
● Command Prompt, Inc (oldest, yes that’s us)
● Crunchy
● Credativ
● OmniTI
● OpenSCG
● 2ndQuadrant
(list goes on and on)

11. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
EnterpriseDB?
● They specialize in a closed source fork not
Open Source PostgreSQL

12. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Tech
● The basics
● Features
● Quirks

13. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
The basics
● ACID Compliant
●
Rich datatypes
– Standards such as varchar(), integer, numeric etc..
– XML, JSON/B, Money, Hstore...
● Rich builtin functions
– to_char(),to_date(),overlaps(),enum_first(),xpath(),greatest(),in(),any(),some(),trim,overlay()...
●
Constraints
– CHECK, PRIMARY KEY, NOT NULL…
● Referential Integrity
– Foreign Keys (Deferrable, Initially Deferred)
● Partitioning
● SCHEMA (namespaces)

14. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Features
● Solid SQL implementation
● Mature code base
● “Enterprise”
● Cool stuff’
● Of note

15. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Solid SQL Implementation
No current version of any database management
system claims full conformance to Core SQL:2011.
PostgreSQL supports most of the major features of
SQL:2011. Out of 179 mandatory features required for
full Core conformance, PostgreSQL conforms to at
least 160. In addition, there is a long list of supported
optional features.

16. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
ISO/IEC SQL Implementation
● ISO/IEC 9075-1 (SQL/Framework)
● ISO/IEC 9075-2 (SQL/Foundation)
● ISO/IEC 9075-9 (SQL/MED)
– FDW, DBI-LINK
● ISO/IEC 9075-11 (SQL/Schemata)
● ISO/IEC 9075-14 (SQL/XML)
– Native XML handling and functions
● ISO/IEC 9075-13 (SQL/JRT(Java))
– PL/JAVA

17. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Mature code base
PostgreSQL started as Ingres at the University
of California, Berkeley in the 1970s.
Current iterations have been in continual
development since 1997.

18. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Enterprise features
● It’s Free! No licensing audits.
● FDW
● Backup and recovery
● Replication
● Table spaces
● Transactional DDL
● UDF
– We don’t have packages

19. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
It’s free. No licensing audits
● Oracle has spawned an entire industry to
defend against the possibility of an audit.
● PostgreSQL has spawned an entire industry
letting businesses and developers use a
database.

20. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
FDW
Foreign Data Wrappers
Connect to external data sources including
Oracle! (CREATE DATABASE LINK)

21. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Backups and Recovery
● Online logical backups (pg_dump/pg_dumpall)
● Online binary backups (pg_basebackup,
pgBackrest, (tar,cpio,cp,rsync))
● Point In Time Recovery (PITR)

22. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Replication
● Logical Replication (pgLogical, Slony, Londiste)
● Binary Replication (Warm,Cold and Hot
Standby). SYNC AND ASYNC
● Load balancing
– Pgpool-II->Master->(n)Slaves

23. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Table Spaces
Postmaster
Warehouse
TBLSpace
Transactional
TBLSpace
Indexes

24. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Transactional DDL
BEGIN;
CREATE TABLE foo (
id BIGSERIAL PRIMARY KEY,
fname TEXT NOT NULL
CHECK(fname ~ ‘[^[:alnum:]_]’)
);
COMMIT/ROLLBACK;
BEGIN;
ALTER TABLE foo ADD COLUMN lname TEXT NOT NULL;
SELECT test_foo_column_laname();
COMMIT/ROLLBACK;

25. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
UDF
● Can be written in a number of languages
– C
– SQL
– PL/PgSQL (similar to PL/SQL)
– Python
– Ruby
– Perl
– V8 (JavaScript)
– Java
– Lots more

26. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Cool stuff
● Savepoints
● Two Phase Commit
– XA
● SELinux integration
● Column, Row permissions (versus just relation)
● Extensions
● GIS/Postgis

27. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Savepoints
● Similar to Oracle:
BEGIN;
INSERT INTO table1 VALUES (1);
SAVEPOINT my_savepoint;
INSERT INTO table1 VALUES (2);
ROLLBACK TO SAVEPOINT my_savepoint;
INSERT INTO table1 VALUES (3);
COMMIT;

28. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Two Phase Commit
● Intended use by external transaction managers
– XA implementation via JDBC driver
● Can be used via SQL
● Review: max_prepared_transactions
configuration parameter
● Always clean up, will interfere with maintenance

29. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
selinux
● For more information
visit:
https://wiki.postgresql.org/wiki/SEPostgreS
QL_SELinux_Overview

30. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Column/Row Permissions
● Column level privs are set using standard
GRANT/REVOKE
● ROW level privs are set via a policy method:
https://www.postgresql.org/docs/9.5/static/ddl-rowsecurity.html

31. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Extensions
● Column Database (Citus)
● Auditing (PgAudit)
● Case insensitive index search (Citext)
● And more (pgxn.org)

32. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Of note
● Use TEXT for CLOB, BYTEA (or lo) for BLOB
● NULL is different:
postgres=# create table bar(a text);
CREATE TABLE
postgres=# insert into bar values('');
postgres=# select * from bar where a IS NULL;
a
---
(0 rows)
postgres=# insert into bar values(NULL);
postgres=# select * from bar where a IS NULL;
a
---
(1 row)
● PostgreSQL has a boolean data type.

33. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
GIS/PostGIS
● Full Geometric support including
– Datatypes
– Functions
● Extended support through PostGIS (external
project).

34. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Of note (2)
● No connect by
– Use “WITH RECURSIVE”
● PostgreSQL is much more reliant on the host
operating system than Oracle. Make sure you
are running an LTS, UNIX (Solaris) or
FreeBSD.

35. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Tools for easing migration
● Ora2pg
– Complete migration toolkit
● Orafce
– Implements compatibility layers that are 10g
compatible including but not limited to:
● Oracle date functions
● Oracle.date data type
● Oracle data operators etc...

36. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
What we don’t have
● No RAC
● No Packages
● No Flashback (on main system, can be
achieved via PITR/Cold standby)

37. Command Prompt, Inc.
http://www.commandprompt.com/
@cmdpromptinc
Questions?
● Business
● Community
● Technical