Data source settings

Use this page to create a data source under a JDBC provider which provides the specific JDBC driver implementation class.

Be sure that you want to use a Version 5.0 data source. If you are using the Enterprise JavaBean component model version 1.0 and Servlets 2.2, you must use a Version 4.0 data source.

To view this administrative console page, click Resources > JDBC Providers > JDBC_provider > Data Sources > data_source.

Configuration tab

Scope
Specifies the level to which this resource definition is visible -- the cell, node, or server level.

Resources such as JDBC Providers, Namespace bindings, or shared libraries can be defined at multiple scopes, with resources defined at more specific scopes overriding duplicates which are defined at more general scopes.

Note that no matter what the scope of a defined resource, the resource's properties only apply at an individual server level. For example, if you define the scope of a data source at the Cell level, all users in that Cell can look up and use that data source, which is unique within that Cell. However, resource property settings are local to each server in the Cell. For example, if you define max connections to 10, then each server in that Cell can have 10 connections.

Cell
The most general scope. Resources defined at the Cell scope are visible from all Nodes and servers, unless they are overridden. To view resources defined in the cell scope, do not specify a server or a node name in the scope selection form.
Node
The default scope for most resource types. Resources defined at the Node scope override any duplicates defined at the Cell scope and are visible to all servers on the same node, unless they are overridden at a server scope on that node. To view resources defined in a node scope, do not specify a server, but select a node name in the scope selection form.
Server
The most specific scope for defining resources. Resources defined at the Server scope override any duplicate resource definitions defined at the Cell scope or parent Node scope and are visible only to a specific server. To view resources defined in a server scope, specify a server name as well as a node name in the scope selection form.

When resources are created, they are always created into the current scope selected in the panel. To view resources in other scopes, specify a different node or server in the scope selection form.

Data type String
Name
Specifies the display name for the data source.

Valid characters for this name include letters and numbers, but NOT most of the special characters. For example you can set this field to Test Data Source. But any name starting with a period (.)or containing special characters ( \ / , : ; " * ? < > | = + & % ' `) is not a valid name.

Data type String
JNDI Name
Specifies the Java Naming and Directory Interface (JNDI) name.

Distributed computing environments often employ naming and directory services to obtain shared components and resources. Naming and directory services associate names with locations, services, information, and resources.

Naming services provide name-to-object mappings. Directory services provide information on objects and the search tools required to locate those objects.

There are many naming and directory service implementations, and the interfaces to them vary. JNDI provides a common interface that is used to access the various naming and directory services.

For example, you can use the name jdbc/markSection.

If you leave this field blank a JNDI name is generated from the name of the data source. For example, a data source name of markSection generates a JNDI name of jdbc/markSection.

After you set this value, save it, and restart the server, you can see this string when you run dumpnamespace.

Data type String
Container managed persistence
Specifies if this data source is used for container managed persistence of enterprise beans.

If the checkbox is selected, a CMP Connector Factory that corresponds to this data source is created for the relational resource adapter.

Data type Checkbox
Default Not checked
Description
Specifies a text description for the resource.
Data type String
Category
Specifies a category string you can use to classify or group the resource.
Data type String
Statement Cache Size
Specifies the number of statements that can be cached per connection. WebSphere Application Server caches a statement after the user closes it.

[5.0 only][Version 5.0.1]The WebSphere Application Server data source optimizes the processing of prepared statements. A prepared statement is a precompiled SQL statement that is stored in a prepared statement object. This object is used to efficiently execute the given SQL statement multiple times.

[Version 5.0.2 and later]The WebSphere Application Server data source optimizes the processing of prepared statements and callable statements by caching those statements that are not being used in an active connection. Both statement types help maximize the performance of transactions between your application and datastore.

  • A prepared statement is a precompiled SQL statement that is stored in a PreparedStatement object. Application Server uses this object to run the SQL statement multiple times (as required by your application run time) with values that are determined by the run time.
  • A callable statement is an SQL statement that contains a call to a stored procedure, which is a series of precompiled statements that perform a task and return a result. The statement is stored in the CallableStatement object. Application Server uses this object to run a stored procedure multiple times (as required by your application run time) with values that are determined by the run time.

If the statement cache is not large enough, useful entries are discarded to make room for new entries. To determine the largest value for your cache size to avoid any cache discards, add the number of uniquely prepared statements and callable statements (as determined by the sql string, concurrency, and the scroll type) for each application that uses this data source on a particular server. This value is the maximum number of cacheable statements for a given connection over the life of the server. Setting the cache size to this value means you never have cache discards. In general, the more statements your application has, the larger the cache should be. For example, if the application has 5 SQL statements, set the statement cache size to 5, so that each connection has 5 statements.

Note: This statement cache size setting is different from WebSphere Application Server V4.0.x. In V4.0.x, the maximum number of possible prepared statements is cached for the data source within an application server. In V5.0, statement cache size is defined on a given physical connection.

In test applications, tuning the statement cache improved throughput by 10-20%. However, because of potential resource limitations, this might not always be possible.

Data type Integer
Default Depends on the database. Most are 10. Informix Version 7.3, 9.2, or 9.3 without latest fix must also be 0. A default of 0 means there is no cache statement.
Datasource Helper Classname
Specifies the datastore helper that is used to perform database specific functions.

This is used by the Relational Resource Adapter at runtime.The default DataStoreHelper implementation class is set based on the JDBC driver implementation class, using the structure: com.ibm.websphere.rsadapter.databaseDataStoreHelper. For example, if the JDBC provider is DB2, then the default DataStoreHelper class is com.ibm.websphere.rsadapter.DB2DataStoreHelper. You can change to your subclass of this DataStoreHelper if necessary.

Data type String
Default Dependent on JDBC driver implentation class
Component-managed Authentication Alias
This alias is used for database authentication in run time.

The Component-managed Authentication Alias is only used when the application resource reference is using res-auth = Application.

If you do not set this field and your database requires the user ID and password to get a connection, then you receive an exception during run time.

If your database (for example, Cloudscape) does not support user ID and password, then do not set the alias in the Component-managed authentication alias or Container-managed authentication alias fields. Otherwise, you see the warning message in the system log to indicate that the user and password are not valid properties. This message is only a warning message, therefore the data source is created successfully.

Data type Pick-list
Container-managed Authentication Alias
This alias is used for database authentication in run time.

The Container-managed Authentication Alias is only used when the application resource reference is using res-auth = Container.

If you do not set this field and your database requires the user ID and password to get a connection, then you receive an exception during run time.

If your database (for example, Cloudscape) does not support user ID and password, then do not set the alias in the Component-managed authentication alias or Container-managed authentication alias fields. Otherwise, you see the warning message in the system log to indicate that the user and password are not valid properties. This message is only a warning message, therefore the data source is created successfully.

Data type Pick-list
Mapping-Configuration Alias
Allows users to select from the Security > JAAS Configuration > Application Logins Configuration list.

The DefaultPrincipalMapping JAAS configuration maps the authentication alias to the userid and password. You may define and use other mapping configurations.

Data type Pick-list

Related concepts
Resource adapter
JDBC providers
Data sources
Related tasks
Creating and configuring a data source using the administrative console
Creating and configuring a JDBC provider using the administrative console
Tuning performance parameter index
Related reference
Administrative console buttons



Searchable topic ID:   Data_source_detail
Last updated: Jun 21, 2007 9:56:50 PM CDT    WebSphere Application Server for z/OS, Version 5.0.2
http://publib.boulder.ibm.com/infocenter/wasinfo/index.jsp?topic=/com.ibm.websphere.zseries.doc/info/zseries/ae/udat_jdbcdatsordet.html

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