The Real Scoop on Migrating from Oracle Databases

The Real Scoop on Migrating from
Oracle Databases

Kevin.Martyn@EnterpriseDB.com
2013-10-30
© 2013 EnterpriseDB Corporation. All rights reserved.

1

Agenda
•  Company Overview
•  What is Postgres Plus Advanced Server?
•  What do we mean by ‘Oracle Compatibility’?
•  What does this mean to you?
•  Migration Methodology
•  How to Migrate
•  Handling migration issues
•  How EnterpriseDB can help
•  Summary
•  Some common questions answered
•  Q&A

2

Providing enterprises with the cost-performance beneﬁts of
Postgres by offering the products, resources, support and
dependability required for high-level commercial applications.!
• 140+ employees
• 2,500+ customers across all market segments
• Global presence with offices in North America, Europe, Asia
• Fast growing: 60%+ YOY sales growth in 2012, 80%+ YOY 2013
• Strong financial banking:

© 2013 EnterpriseDB. All rights reserved.

3

New Gartner ODBMS Magic Quadrant
Gartner Comments:
•  Community leadership — EnterpriseDB
is the primary contributor to the
PostgreSQL community and is responsible
for many new features of PostgreSQL,
including JSON.
•  Functionality — The functionality of
EnterpriseDB's Postgres Plus has
increased greatly, and with the Oracle
Compatibility Feature is now more than
sufficient to run both mission-critical and
non-mission-critical applications.
•  Stability and compatibility —
References specifically call out
compatibility with Oracle, the stability of the
DBMS and product support as strengths.


4

Agenda
•  Summary
•  Q&A

5

Postgres Plus: A Super-Set of Features
Synchronized with and contributing to the PostgreSQL community


6

What Is Postgres Plus Advanced Server?

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Superset of community
PostgreSQL
10th generation of Oracle
compatibility, since 2005
World-class security add-ons
Performance that rivals any other
proprietary RDBMS
Enterprise-class developer and
DBA tools
Installation, performance tuning,
and maintenance services
Software indemnification

Agenda
•  Summary
•  Q&A

8

Oracle Compatibility - Goals
•  Run applications written for Oracle virtually unchanged
•  No need to re-train Oracle DBAs and developers
•  Support for SQL, PL/SQL, OCI and Pro*C
•  Replication for easy sharing of data
•  Dramatic Cost Savings
•  No Vendor Lock-in


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Compatibility means:
•  SQL extension support
−  Decode, NVL, Substr, NVL2
−  Date/time functions: add_months, extract, next_day

•  PL/SQL support
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REF Cursors, Implicit and explicit cursors
Looping, variable declarations, conditional statements
Collections: Associative Arrays, Varrays, Nested tables
Bulk binding
Named parameters
User Defined Exceptions
Explicit Transaction Control
−  within a stored procedure
−  (not supported by PostgreSQL)


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Compatibility means: (cont.)
•  Features
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Packages
Stored procedures
Functions
Triggers
Hints
Database Links
Hierarchical Queries
Materialized view (foundation) (*1)
Synonyms – Public and Private
Sequences
Rownum
Object types
−  Create type … as object, … as table, …as varray
−  Constructor and collection methods

−  Users/Roles
−  Dynamic SQL


*1 – PPAS 9.3

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•  Data Types
Integer, number, char, double precision,
float, varchar2, blob, clob, xmltype, rowid

•  Built-in Packages
DBMS_:
SQL, RLS, LOB, JOB, PIPE, ALERT, OUTPUT, UTILITY, PROFILER
RANDOM, LOCK, CRYPTO, SCHEDULER, MVIEW (*1)

UTL_:
FILE, MAIL, SMTP, ENCODE, TCP
HTTP, URL (*1)

REGEXP_:
INSTR, SUBSTR, COUNT (*1)

•  Oracle-like Data Dictionary
−  ALL_, DBA_, USER_ views
−  Most commonly accessed views
*1 – PPAS 9.3


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•  Diagnostics - DRITA
−  System and session waits
−  Not exposed in PostgreSQL
−  Part of Advanced Server

−  Statspack like reporting

•  Tools
−  EDB*Plus
−  EDB*Loader
−  EDB*Wrap

(SQL*Plus look-a-like)
(SQL*Loader equivalent)
(similar to the PL/SQL wrapper)

*1 – PPAS 9.3


13

Partitioning in PPAS v9.3
Partitioning Performance: PPAS 9.3 v. PostgreSQL 9.3 v. PPAS 9.2
PPAS 9.2

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PostgreSQL 9.3

Improvement Factor

70

PPAS 9.3

60
50
40

76 times Faster!

30
20
10
0
250

500

1000

Number of Table Partitions

•  Oracle syntax for partitioning (create, add, exchange, split, …)
•  Postgres Plus Advanced Server is up to 76 times faster for data
retrieval than PostgreSQL 9.3 or PPAS 9.2 (Partition pruning, and inserts)
•  The greater the number partitions, the greater the performance benefits


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Agenda
•  Summary
•  Q&A

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Migration Example


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Database Migration Toolkit
•  Online Migration Toolkit enables point and click migration from
Oracle
•  Automatically Migrates:
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Data
Schemas
Stored Procedures
Triggers
Functions


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Sequences
Packages
Views
Database Links
Synonyms

Oracle Compatibility & Migration Strategies
Strategy

Benefits

Develop/Deploy
New LOB Applications

§ Significant cost savings for non mission critical
systems
§ Leverages all existing Oracle skills
§ Very low risk

Deploy Postgres Plus
as Oracle
Replication Server

§ Significant cost savings
§ Leverages Postgres Plus Replication Server
§ Improves transaction and query performance

Migrate non Mission
Critical Oracle Apps to
Postgres Plus

§ Significant cost savings
§ Very low risk

Migrate Mission Critical
Oracle Apps to
Postgres Plus

§ Biggest cost savings
§ Greatest deployment flexibility


18

Agenda
•  Summary
•  Q&A

19

Multi-phase Migration Process
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Phase I – Planning
• 

Determine what application to migrate"
– 
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Home grown applications!
Java, C!
Packaged applications that support multiple databases!
Support JDBC, ODBC"

Once candidate applications are chosen, sign up for OMA"
Oracle Migration Assessment (OMA) Identiﬁes:"
–  Possible migration issues!
–  Gives time estimate to migrate system"

• 

Establish migration team:"
–  Need source system knowledgeable resource!
–  Need target system knowledgeable resource"

• 

Establish project plan with milestones


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•  Phase II – Prepare Environment
−  Obtain and install necessary software
−  Establish connectivity between systems
−  Copy the Oracle JDBC jar file to jre/lib/ext directory in Postgres Plus Advanced
Server Installation

•  Phase III – Migrate Schema
−  Use Migration Toolkit in schema only mode
−  Resolve issues here before going to next phase

•  Phase IV – Migrate Data
−  Use command line MTK
−  Use –copyViaDBLinkOra
− 

Uses OCI to connect to Oracle

−  Use parallel threads

−  Use dblink_ora_copy function directly to bypass logging
−  Export Oracle data to flat files, load using EDB*Loader


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•  Phase V – Port Application
−  Change connection information
−  Recompile /Link application (OCI or Pro*C)

•  Phase VI – Test
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Verify application functionality
Address issues
Test performance
Tune

•  Phase VII Integration
−  Establish co-existence strategy
−  Setup database links to other databases
−  Setup replication between Oracle or SQL Server and Postgres
Plus Advanced Server

•  Phase VIII – Rollout
−  System becomes production
22

22

Agenda
•  Summary
•  Q&A

23

Phase I Oracle Migration Assessment
Work Products
•  Detailed OMA Analysis Report

•  List of known workarounds
•  Technology risks
•  Compatibility Score
•  Proposed migration approach including skills requirements,
training, architecture support, developer subscription, and
development resources

24

Phase I Setup MTK Environment
•  Establish connectivity
−  Copy Oracle JDBC jar file to Postgres Plus Advanced Server install
cp /usr/lib/oracle/xe/app/oracle/product/11.2.0/server/jdbc/lib/ojdbc14.jar /opt/
PostgresPlus/9.2AS/jre/lib/ext
−  Edit the toolkit.properties file to contain Oracle and Postgres Plus Advanced
Server connection information:
SRC_DB_URL=jdbc:oracle:thin:@localhost:1521:xe
SRC_DB_USER=system
SRC_DB_PASSWORD=manager
TARGET_DB_URL=jdbc:edb://localhost:5999/demo
TARGET_DB_USER=demo
TARGET_DB_PASSWORD=manager


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Phase II Oracle Migration Toolkit
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*** Checking for Migration Issues ***
Object Type
Type
Count
------------------------------------------------------------------------------TRIGGER
Count
0
SOURCE
Package
0
SOURCE
Syntax - Exception
0
SOURCE
Function
789
SOURCE
Syntax - Object
0
SOURCE
Syntax - Other
792
SOURCE
Syntax - Hints
282
SOURCE
Syntax - Exp Trans Ctl
730
SOURCE
Total Count
2623
COLLECTION
Count
1
VARRAY
Count
0
DIMENSION
Count
0
JOB
Count
0
MATERIALIZED VIEW
Count
0
RESOURCE MGR
Count
0
POLICY
Count
9
PROFILE
Count
6
SUMMARY
Possible Migration Issues
2775


26

Phase III Migrate Schema
Use MTK in schema only mode:
[enterprisedb@localhost bin]$ ./runMTK.sh -schemaOnly hr
Source database connectivity info...
conn =jdbc:oracle:thin:@localhost:1521:xe
user =system
password=******
Target database connectivity info...
conn =jdbc:edb://localhost:5999/demo
user =demo
password=******
Connecting with source Oracle database server...
Connecting with target EnterpriseDB database server...
Importing redwood schema hr...
Creating Schema...hr
Creating Object Type: NUMLIST
Creating Sequence: EMPLOYEES_SEQ
Creating Tables...
Creating Table: EMPLOYEES


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Phase III Migrate Schema con’t
******************** Migration Summary ********************
Object Types: 9 out of 9
Sequences: 3 out of 3
Tables: 49 out of 53
Constraints: 39 out of 40
Procedures: 7 out of 7
Functions: 3 out of 3
Packages: 3 out of 3
Total objects: 139
Successful count: 134
Failure count: 5
List of failed objects
======================
Tables
-------------------1. HR.BFTEST
2. HR.TESTBD
3. HR.TESTBF
4. HR.TESTCNTXT


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•  Migration logs stored in user’s home directory :
/home/enterprisedb/.enterprisedb/migration-toolkit/logs

•  Resolve issues:
Error Creating Table TESTCNTXT:ERROR: function sys_context(unknown,
unknown) does not exist
Hint: No function matches the given name and argument types. You might need to
add explicit type casts.

CAUSE: this table used SYS_CONTEXT(‘USERENV’,’CURRENT_USER’) as a
DEFAULT value
RESOLUTION: use CURRENT_USER function instead


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•  Migration logs stored in user’s home directory :
•  Resolve issues:
XMLELEMENT : 35
There is a similar function in Postgres with the same name but the syntax is slightly
different.
SELECT xmlelement(name foo, xmlattributes(current_date as bar), 'cont', 'ent');
xmlelement
------------------------------------<foo bar="2007-01-26">content</foo>


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Phase IV Migrate Data
•  Use MTK in data only mode:
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[enterprisedb@localhost bin]$ ./runMTK.sh -dataOnly hr
Source database connectivity info...
conn =jdbc:oracle:thin:@localhost:1521:xe
user =system
password=******
Target database connectivity info...
conn =jdbc:edb://localhost:5999/demo
user =demo
password=******
Connecting with source Oracle database server...
Connecting with target EnterpriseDB database server...
Importing redwood schema hr...
Loading Table Data in 8 MB batches...
Loading Table: AGES ...
[AGES] Migrated 1 rows.
[AGES] Table Data Load Summary: Total Time(s): 0.467 Total Rows: 1
Loading Table: DEPARTMENTS ...


31

Phase V Port the Application
§  Change Application Connection method
§  Java application =
§  Old connection syntax:
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection con = DriverManager.getConnection("jdbc:oracle:thin:@localhost:
1521:xe”,”hrapp”,”manager”);

§  New connection syntax:
Class.forName("com.edb.Driver");
Connection con = DriverManager.getConnection("jdbc:edb://localhost:5444/edb",
“hrapp",“manager");


32

Agenda
•  Summary
•  Q&A

33

Handling Issues
•  Not all migrations are error free
−  Migration log will contain all errors

•  Some common issues:
−  Column delimiter chosen is in column data
−  Causes ‘Extra data found’ error
−  Resolve by using different delimiter

•  Oracle built-in package does not exist
−  DBMS_AQ – we use solutions like ActiveMQ, MQSeries or Tibco
−  Or own code. Enqueue and dequeue procedures are fairly easy to code
−  xDB Replication Server can also be used since based on pub/sub architecture
−  DBMS_LOCK.sleep – use pg_sleep function instead

•  Oracle feature not supported
−  MERGE command not supported
−  Can be rewritten to use INSERT and UPDATE with checks

−  Index Organized Tables
−  Cluster a table using CLUSTER command for same read performance gain


34

Handling Issues (continued)
•  Database Links
−  Migrated over by tool but password is invalid
−  This is because Oracle hides the password
−  Resolve by dropping and recreating
−  Or by specifying a password to use when running the MTK
−  runMTK -allDBLinks LINK_NAME1=abc,LINK_NAME2=xyz HR

•  Data Movement – performance
−  Migration toolkit connects via jdbc
−  Large datasets are slow to move
−  Use database link functionality instead
−  Dblink_ora_copy – EnterpriseDB method to copy data from Oracle over OCI
−  Much faster

−  OR extract data from Oracle to csv files, load using edbldr


35

Tuning Recommendations
•  Use DynaTune
−  Dynamically adjusts database configuration based on available resources
−  Set via edb_dynatune parameter
−  Values 0 – 100 corresponding to % of machines to use

•  Remember to analyze database
−  Use Analyze command

•  Oracle Hints supported
−  No need to remove from embedded SQL


36

Agenda
•  Summary
•  Q&A

37

How EnterpriseDB Can Help

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Oracle Migration Assessment
•  Paid for service from EnterpriseDB
•  What is it?
−  Pre-analysis interview
−  Analysis of Oracle schemas to be migrated
−  Finds possible migration issues
−  Unsupported Features
−  Unsupported Syntax
−  Implementation Differences

−  Findings documented in final report
−  Post analysis discussions to review findings

•  Migration feasibility score assigned (1 – 10)
http://www.enterprisedb.com/solutions/oracle-migration-assessment


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Professional services for your migration
Assist after the OMA
•  Plan rollout
•  Migration the Schema and Stored procedures (OMF next)
•  Migrate the data (once, 2x,… minimal down time)
•  Training
•  Port and test application(s) (typically customer)
•  DBA and application coaching/support
•  Support contract
•  Remote DBA


40

Oracle Migration Factory Core Services
•  Customer provides data-less Oracle export of database
•  Migrate the database(s) to Postgres Plus Advanced Server
−  Resolve any issues
−  Implement workarounds for missing or different functionality
−  Perform sanity checking of unit functionality
−  Requires input/output from customer on same units in Oracle

•  Document the changes/workarounds
•  Educate Customer on changes/workarounds
−  Advise on application level changes needed

•  Return migrated databases to Customer
−  Via pg_dump

•  Customer can customize with add on options


41

Oracle Migration Factory Add-ons
•  Setup and Migrate test system
−  Installation of Postgres Plus Advanced Server on Customer server
−  Import of migrated database to Postgres Plus Advanced Server
−  Migration of test data from a test Oracle system

•  Application Functional Testing
−  Provide assistance in connecting application to database
−  Provide assistance in functional testing of application
−  Resolve functional testing issues

•  Performance Tuning of Migrated System
•  Production Migration Setup
−  Install Postgres Plus Advanced Server on target production server
−  Import migrated database from testing server
−  Setup of xDB Replication Server
−  Snapshot process will migrate production Oracle data
−  Deltas are captured by xDB triggers
−  Once snapshot is done, synchronization is performed


42

Agenda
•  Summary
•  Q&A

43

Summary
•  Migrations are no longer impossible
•  Compatibility provides
−  Lower cost of migrations
−  Shorter migration timelines
−  Lower risk (you can always go back)

•  EnterpriseDB provides
−  Oracle compatibility
−  Automated tools to migrate from Oracle
−  And others: MySQL, Sybase, SQL Server (data & schema)

•  Migration Expertise for:
− 
− 
− 
− 

Planning
Performing migration
Testing
Rollout

http://www.enterprisedb.com/solutions/oracle-compatibility


44

EDB Serves ALL Your Postgres Needs

PostgreSQL


Postgres Plus
Advanced Server

45

Postgres Plus
Cloud

Agenda
•  Summary
•  Q&A

46

Some Common
Questions
Answered

47

47

How can I replace RAC for HA?

§  Active/Passive Clustering is
proven technology
§  Provides fast detection and
failover
§  No extra database cost


48

How can I replace DataGuard(Physical)?

Postgres Plus
Advanced Server

Postgres Plus
Advanced Server

Live
Server
Instance

pg_standby

WAL
Disk
Storage


Standby
Server
(in recovery mode)

WAL

Archiver

49

Disk
Storage

How can I replace DataGuard(Logical)?
» Uses WAL for speed and
reliability
» Highly cost effective, uses
commodity servers
» Excellent HA solution when
clustering is not an option


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The Real Scoop on Migrating from Oracle Databases

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