Introducing JDBC

1 Introducing JDBC

Java Database Connectivity (JDBC) is a Java standard that provides the interface for connecting from Java to relational databases. The JDBC standard is defined and implemented through the standard java.sql interfaces. This enables individual providers to implement and extend the standard with their own JDBC drivers. JDBC is based on the X/Open SQL Call Level Interface (CLI). JDBC 4.0 complies with the SQL 2003 standard.

This chapter provides an overview of the Oracle implementation of JDBC, covering the following topics:

1.1 Overview of Oracle JDBC Drivers

In addition to supporting the standard JDBC application programming interfaces (APIs), Oracle drivers have extensions to support Oracle-specific data types and to enhance performance.

Oracle provides the following JDBC drivers:

Thin driver

The JDBC Thin driver is a pure Java, Type IV driver that can be used in applications. It is platform-independent and does not require any additional Oracle software on the client-side. The JDBC Thin driver communicates with the server using Oracle Net Services to access Oracle Database.

The JDBC Thin driver enables a direct connection to the database by providing an implementation of Oracle Net Services on top of Java sockets. The driver supports the TCP/IP protocol and requires a TNS listener on the TCP/IP sockets on the database server.

Note:

Oracle recommends you to use the Thin driver unless you have a feature that is supported only by a specific driver.
Oracle Call Interface (OCI) driver

It is used on the client-side with an Oracle client installation. It can be used only with applications.

The JDBC OCI driver is a Type II driver used with Java applications. It requires platform-specific OCI libraries. It supports all installed Oracle Net adapters, including interprocess communication (IPC), named pipes, TCP/IP, and Internetwork Packet Exchange/Sequenced Packet Exchange (IPX/SPX).

The JDBC OCI driver, written in a combination of Java and C, converts JDBC invocations to calls to OCI, using native methods to call C-entry points. These calls communicate with the database using Oracle Net Services.

The JDBC OCI driver uses the OCI libraries, C-entry points, Oracle Net, core libraries, and other necessary files on the client computer where it is installed.

OCI is an API that enables you to create applications that use the native procedures or function calls of a third-generation language to access Oracle Database and control all phases of the SQL statement processing.
Server-side Thin driver

It is functionally similar to the client-side Thin driver. However, it is used for code that runs on the database server and needs to access another session either on the same server or on a remote server on any tier.

The JDBC server-side Thin driver offers the same functionality as the JDBC Thin driver that runs on the client-side. However, the JDBC server-side Thin driver runs inside Oracle Database and accesses a remote database or a different session on the same database for use with Java in the database.

This driver is useful in the following scenarios:
- Accessing a remote database server from an Oracle Database instance acting as a middle tier
- Accessing an Oracle Database session from inside another, such as from a Java stored procedure
The use of JDBC Thin driver from a client application or from inside a server does not affect the code.
Server-side internal driver

It is used for code that runs on the database server and accesses the same session. That is, the code runs and accesses data from a single Oracle session.

The JDBC server-side internal driver supports any Java code that runs inside Oracle Database, such as in a Java stored procedure, and accesses the same database. It lets the Oracle Java Virtual Machine (Oracle JVM) to communicate directly with the SQL engine for use with Java in the database.

The JDBC server-side internal driver, the Oracle JVM, the database, and the SQL engine all run within the same address space, and therefore, the issue of network round-trips is irrelevant. The programs access the SQL engine by using function calls.

Note:

The server-side internal driver does not support the cancel and setQueryTimeout methods of the Statement class.

The JDBC server-side internal driver is fully consistent with the client-side drivers and supports the same features and extensions.

The following figure illustrates the architecture of Oracle JDBC drivers and Oracle Database.

Figure 1-1 Architecture of Oracle JDBC Drivers and Oracle Database

Description of "Figure 1-1 Architecture of Oracle JDBC Drivers and Oracle Database"

Related Topics

1.2 Choosing the Appropriate Driver

Consider the following when choosing a JDBC driver for your application or applet:

In general, unless you need OCI-specific features, such as support for non-TCP/IP networks, use the JDBC Thin driver.
If you want maximum portability and performance, then use the JDBC Thin driver. You can connect to Oracle Database from an application using the JDBC Thin driver.
If you want to use Lightweight Directory Access Protocol (LDAP) over Secure Sockets Layer (SSL)/Transport Layer Security (TLS), then use the JDBC Thin driver.
If you are writing a client application for an Oracle client environment and need OCI-driver-specific features, such as support for non-TCP/IP networks, then use the JDBC OCI driver.
For code that runs in the database server and needs to access a remote database or another session within the same database instance, use the JDBC server-side Thin driver.
If your code runs inside the database server and needs to access data locally within the session, then use the JDBC server-side internal driver to access that server.

1.3 Feature Differences Between JDBC OCI and Thin Drivers

Table 1-1 lists the features that are specific either to the JDBC OCI or JDBC Thin driver in Oracle Database Release 18c.

Table 1-1 Feature Differences Between JDBC OCI and JDBC Thin Drivers

JDBC OCI Driver	JDBC Thin Driver
OCI connection pooling	NA
NA	Default support for Native XA
Transparent Application Failover (TAF)	NA
NA	Application Continuity
NA	Transaction Guard
NA	Support for row count per iteration for array DML
NA	SHA-2 Support in Oracle Advanced Security
`oraaccess.xml` configuration file settings	NA
NA	Oracle Advanced Queuing
NA	Continuous Query Notification
NA	Support for the `O7L_MR` client ability
NA	Support for promoting a local transaction to a global transaction

Note:

The OCI optimized fetch feature is internal to the JDBC OCI driver and not applicable to the JDBC Thin driver.
Some JDBC OCI driver features, inherited from the OCI library, are not available in the Thin JDBC driver.

1.4 Environments and Support

This section provides a brief discussion of the following topics:

1.4.1 Supported JDK and JDBC Versions

In Oracle Database 12c Release 2 (12.2.0.1), all the JDBC drivers are compatible with JDK 8. Support for JDK 8 is provided through the ojdbc8.jarfile.

Related Topics

1.4.2 JNI and Java Environments

The JDBC OCI driver uses the standard Java Native Interface (JNI) to call OCI C libraries. You can use the JDBC OCI driver with Java Virtual Machines (JVMs), in particular, with Microsoft and IBM JVMs.

1.4.3 JDBC and IDEs

The Oracle JDeveloper Suite provides developers with a single, integrated set of products to build, debug, and deploy component-based database applications for the Internet. The Oracle JDeveloper environment contains integrated support for JDBC, including the JDBC Thin driver and the native OCI driver. The database component of Oracle JDeveloper uses the JDBC drivers to manage the connection between the application running on the client and the server.

1.5 Feature List

The following table lists the features and the versions in which they were first supported for each of the three Oracle JDBC drivers: server-side internal driver, JDBC OCI driver, and JDBC Thin driver.

Table 1-2 Feature List

Feature	Server-Side Internal	JDBC OCI	JDBC Thin
JDK 1.0		7.2.2	7.2.2
JDBC 1.0.2		7.2.2	7.2.2
JDK 1.1.1		8.0.6	8.0.6
JDBC 1.22 (No new features; just minor revisions)		8.0.6	8.0.6
defineColumnType^Foot 1		8.0.6	8.0.6
Row Prefetch		8.0.6	8.0.6
Java Native Interface		8.1.6
JDK 1.2	9.0.1	8.1.6	8.1.6
JDBC 2.0 SQL3 Types (`BLOB`, `CLOB`, `Struct`, `Array`, `REF`)	8.1.5	8.1.5	8.1.5
Native LOB		8.1.6	9.2.0
Associative Arrays^Foot 2	10.2.0	8.1.6	10.1.0
JDBC 2.0 Scrollable Result Sets	8.1.6	8.1.6	8.1.6
JDBC 2.0 Updatable Result Sets	8.1.6	8.1.6	8.1.6
JDBC 2.0 Standard Batching	8.1.6	8.1.6	8.1.6
JDBC 2.0 Connection Pooling	NA	8.1.6	8.1.6
JDBC 2.0 XA	8.1.6	8.1.6	8.1.6
Server-side Thin driver	8.1.6	NA	NA
JDBC 2.0 RowSets		9.0.1	9.0.1
Implicit Statement Caching	8.1.7	8.1.7	8.1.7
Explicit Statement Caching	8.1.7	8.1.7	8.1.7
Temporary LOBs	9.0.1	9.0.1	9.0.1
Object Type Inheritance	9.0.1	9.0.1	9.0.1
Multilevel Collections	9.0.1	9.0.1	9.0.1
`oracle.jdbc` Interfaces	9.0.1	9.0.1	9.0.1
Native XA		9.0.1	10.1.0
OCI Connection Pooling	NA	9.0.1	NA
TAF	NA	9.0.1	NA
NLS Support	9.0.1	9.0.1	9.0.1
JDK 1.3	9.2.0	9.2.0	9.2.0
JDK 1.4	10.1.0	9.2.0	9.2.0
JDBC 3.0 Savepoints	9.2.0	9.2.0	9.2.0
New Statement Caching API	9.2.0	9.2.0	9.2.0
ConnectionCacheImpl connection cache	NA	8.1.7	8.1.7
Implicit Connection Cache	NA	10.1.0	10.1.0
Fast Connection Failover		10.1.0.3	10.1.0.3
Connection Wrapping		9.2.0	9.2.0
DMS		9.2.0	9.2.0
Service Names in URLs		9.2.0	10.2.0
JDBC 3.0 Connection Pooling Properties	NA	10.1.0	10.1.0
JDBC 3.0 Updatable BLOB, CLOB, REF	10.1.0	10.1.0	10.1.0
JDBC 3.0 Multiple Open Result Sets	10.1.0	10.1.0	10.1.0
JDBC 3.0 Parameter Metadata	10.1.0	10.1.0	10.1.0
JDBC 3.0 Set/Get Stored Procedures Parameters by Name	10.1.0	10.1.0	10.1.0
JDBC 3.0 Statement Pooling	10.1.0	10.1.0	10.1.0
Set Statement Parameters by Name	10.1.0	10.1.0	10.1.0
End-to-End Tracing		10.1.0	10.1.0
Web RowSet	11.1	10.1.0	10.1.0
Proxy Authentication		10.2.0	10.1.0
JDBC 3.0 Auto Generated Keys		10.2.0	10.2.0
JDBC 3.0 Holdable Cursors	10.2.0	10.2.0	10.2.0
JDBC 3.0 Local/Global Transaction Switching	9.2.0	9.2.0	9.2.0
Run-time Connection Load Balancing	NA	10.2.0	10.2.0
Extended `setXXX` and `getXXX` for LOBs		10.2.0	10.2.0
XA Connection Cache	NA	10.2.0	10.2.0
DML Returning		10.2.0	10.2.0
JSR 114 RowSets		10.2.0	10.2.0
SSL/TLS Encryption		9.2.0	10.2.0
SSL/TLS Authentication		9.2.0	11.1
JDK 5.0	11.1	11.1	11.1
JDK 6		11.1	11.1
JDBC 4.0		11.1	11.1
AES Encryption			11.1
SHA1 Hash			11.1
Radius Authentication		10.2.0	11.1
Kerberos Authentication			11.1
ANYDATA and ANYTYPE types		11.1	11.1
Native AQ			11.1
Query Change Notification			11.1
Database startup and shutdown	NA	11.1	11.1
Factory methods for data types	11.1	11.1	11.1
Buffer Cache	11.1	11.1	11.1
Secure Files	11.1	11.1	11.1
Diagnosability	11.1	11.1	11.1
Client Result Cache		11.1.0	18.1
Server Result Cache	11.1	11.1.0	11.1.0
Universal Connection Pool		11.1.0.7.0	11.1.0.7.0
TimeZone Patching		11.2	11.2
Secure Lob Support		11.2	11.2
Lob prefetch Support		11.2	11.2
Network Connection Pool			11.2
Column Security Support			11.2
XMLType Queue Support (AQ)			11.2
Notification Grouping (AQ and DCN)			11.2
SimpleFAN		11.2	11.2
Application Continuity			12.1
Transaction Guard			12.1
SQL Statement Translation			12.1
Database Resident Connection Pooling		12.1	12.1
Latest JDBC Standard Support		12.1	12.1
SHA-2 Support in Oracle Advanced Security			12.1
Invisible Columns Support		12.1	12.1
Support for PL/SQL Package Types as Parameters		12.1	12.1
Support for Monitoring of Database Operations		12.1	12.1
Support for Increased Length Limit for Various Data Types		12.1	12.1
Implicit Results Support		12.1	12.1
Support for row count per iteration for array DML			12.1
`oraaccess.xml` configuration file settings		12.1

^Footnote 1

Starting from Oracle Database 12c Release 1 (12.1), most of the variants of this method have been deprecated. The current versions only enable to perform LOB to LONG conversions and configure the LOB prefetch size.

^Footnote 2

Associative Arrays were previously known as index-by tables.

Note:

In the table, NA means that the feature is not applicable for the corresponding Oracle JDBC driver.
The ConnectionCacheImpl connection cache feature is deprecated since Oracle Database 10g.
The Implicit Connection Cache feature is desupported from this release.