DB-1: Understanding and Leveraging the Latest ODBC and JDBC Technology What’s new in OpenEdge®...

DB-1: Understanding and Leveraging the Latest ODBC and JDBC Technology

What’s new in OpenEdge® 10.1A?

Rob StewardDirector of Software Development

© 2006 Progress Software Corporation2DB-1: Understanding & Leveraging Latest ODBC and JDBC Technology

Agenda

ODBC architecture changes ODBC Unicode functionality JDBC architecture changes JDBC JTA support

What’s New in 10.1A?


Agenda




ODBC “Classic” Architecture

Application Code

Driver Manager

ODBCDriver

A

ODBCDriver

B

ODBCDriver

C

NetworkLib

NetworkLib

NetworkLib

A B C

•Data Protocol•Wire Protocol


ODBC Wire Protocol Architecture

Application Code

Driver Manager

ODBCDriver

A

ODBCDriver

B

ODBCDriver

C

A B C

•Data Protocol•Wire Protocol

OpenEdge Wire Protocol Driver

•Higher Performance•No Dependencies•Thin client install


OpenEdge Wire Protocol Advantages

Ease of Deployment

Versioning• 10.1A will be forward compatible with future

versions of the database

Better performance


How Database Middleware Works

DBMSSERVER

Packets sentfrom driver

2

Packets sentback fromDBMS Server

3

DRIVER

API CALL

DATABASENETWORK

NETWORK

select * fromemployees where location = ‘boston’

Applicationmakes a call

1


Why better performance?

NETWORK

NETWORK

SIMULTANEOUS

Applicationmakes a call

Packets sentfrom driver

Packets sentback fromDBMS Server

1

2

3

3

BUFFER

Private BUFFER

Only one network read to process allpackets. This occurs simultaneously asthe DBMS server sends more packets

DRIVER

API CALL

DBMSSERVER

DATABASE

different sized packets


ODBC Wire Protocol Availability

New driver available in 10.1A!• Compatible with 10.1A servers

Platforms• Windows 98/Me/NT/2000/XP/2003• AIX• Solaris• HP-UX


Agenda




What is Unicode?

One character set standard to rule them all A single encoding standard to represent “all” written

characters-glyphs Unicode 4.0 contains over 96,000 characters Three Common Flavors

• UCS-2 (strictly 2 bytes)

• UTF-8 (1 to 4 bytes; preserves ASCII; favored by Unix)

• UTF-16 (UCS-2 + surrogates)


Why Unicode?

Internationalizes your code

Performance – can avoid costly character set translations


Unicode Support in the ODBC Standard

Unicode support added in version 3.5 Spec assumes UCS-2 Separate API calls for Unicode strings (“W” functions) Separate data types for Unicode strings (SQL_C_WCHAR) ODBC Driver Manager masks driver and application

differences


What does Unicode Support Encompass at the ODBC API level?

Arguments to API functions/methods String parameters String results


How does Unicode work in ODBC?

Unicode App vs. non-Unicode app. • “W” functions

Unicode Driver vs. non-Unicode driver. • SQLConnectW exported?


How does Unicode work in ODBC? (cont.)

DM tries to make all possible combinations work.• ANSI App w/ ANSI driver

• Unicode App w/ Unicode driver

• ANSI App w/ Unicode driver

• Unicode App w/ ANSI driver (obvious limitations)

• Unix Only: UTF8 app w/ UTF-16 driver.

• Unix Only: UTF-16 app w/ UTF8 driver.


Why are Character Set Conversions Bad?

Degrades performance. Frequently data is lost (Substituted), or corrupted

during conversions. For example, here’s how the Euro character, “€”, is

represented in various character sets:

ISO8859-1: N/A

Cp1252: 0x80

UCS-2/UTF-16: 0x20AC

UTF-8 : 0xE2A2AC


When are Conversions Necessary and Why?

Conversions by DM• Non-Unicode apps

• Non-Unicode drivers

Conversions by Unicode Driver• Between Unicode and DB codepage for

SQL when DB’s codepage is not Unicode

• Conversions for parameters and result columns as necessary based on C type and SQL type


Agenda




Architecture differences in JDBC drivers

The JDBC specification formally defines 4 different types of drivers• Type 1: JDBC-ODBC bridge

• Type 2: partial Java™ driver

• Type 3: pure Java driver for database middleware

• Type 4: pure Java driver for direct-to-database


JDBC Architecture – Type 1

•Authored by DataDirect•Free with JDK•JDBC 2.0 API•For Prototyping

ODBC Driver Manager

ODBCDriver

A

ODBCDriver

B

ODBCDriver

C

A B C

JDBC/ODBC BridgeApplication Code



Application Code

JDBCDriver

A

JDBCDriver

B

JDBCDriver

C

NetworkLib

NetworkLib

NetworkLib

A B C

•Platform Dependent



Application Code

JDBCDriver

A

JDBCDriver

B

JDBCDriver

C

A B C

OpenEdge 10.1A Type 4 Driver

•No Client Dependencies•More Platforms•Better Performance


JDBC Architecture

OpenEdge 10.1A Driver• Type 4

• JDBC 3.0 API

• CTS Certified

Java Application Code

JDBCDriver

A

JDBCDriver

B

JDBCDriver

C

A B C


OpenEdge Type 4 JDBC Advantages

Ease of Deployment

Versioning• No dependence on native code

No platform dependence• Any J2SE 1.4 or higher

Better performance


Agenda




What is JTA?

JTA is the Java Transaction API

JTA specifies standard Java interfaces between a transaction manager and the parties involved in a distributed transaction system: the resource manager, the application server, and the transactional applications.

JTA is based on the XA specification


Why is JTA important?

All common application servers support XA transactions through JTA and they will use them if necessary and available

If you need to enlist OpenEdge connections in a distributed transaction with some other data source


How Does JTA work?

1 UserTransaction

javax.transaction.UserTransaction

Provides the application the ability to control transaction boundaries. It starts a

global transaction and associates the transaction with the calling thread.

2 TransactionManager

javax.transaction.TransactionManager

Allows the application server to control transaction boundaries on behalf of the

application being managed.

3 XAResource javax.transaction.xa.XAResource

A Java mapping of the industry standard XA interface.


A Distributed Transaction with JTA

. . .

xaDS = getDataSource();

xaCon = xaDS.getXAConnection("jdbc_user", "jdbc_password");

xaRes = xaCon.getXAResource();

con = xaCon.getConnection();

stmt = con.createStatement();

xid = new MyXid(100, new byte[]{0x01}, new byte[]{0x02});


A Distributed Transaction with JTA

xaRes.start(xid, XAResource.TMNOFLAGS);

stmt.executeUpdate("insert into test_table values (100)");

xaRes.end(xid, XAResource.TMSUCCESS);

ret = xaRes.prepare(xid);

if (ret == XAResource.XA_OK) { xaRes.commit(xid, false);

}...


Questions?


Thank you foryour time


Date post:	05-Jan-2016
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