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Siebel Analytics Server Administration Guide > Working in a Repository's Physical Layer > Physical Layer Objects >

Working with Connection Pools

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A connection pool contains information about the connection between the Siebel Analytics Server and a data source. The Physical layer in the Administration Tool contains at least one connection pool for each database. You can configure multiple connection pools for a database. Connection pools allow multiple concurrent data source requests (queries) to share a single database connection, reducing the overhead of connecting to a database.

For each connection pool, you must specify the maximum number of concurrent connections allowed. Once this limit is reached, the Analytics server routes all other connection requests to another connection pool or, if no other connection pools exist, the connection request waits until a connection becomes available.

Increasing the allowed number of concurrent connections can potentially increase the load on the underlying database accessed by the connection pool. Test and consult with your DBA to make sure the data source can handle the number of connections specified in the connection pool. Also, if the data sources have a charge back system based on the number of connections, you might want to limit the number of concurrent connections to keep the charge back costs down.

In addition to the potential load and costs associated with the database resources, the Siebel Analytics Server allocates shared memory for each connection upon server startup. Therefore, raising the number of connections increases Siebel Analytics Server memory usage.

This section includes the following topics:

Creating or Editing a Connection Pool
Setting Properties for an XML Data Source

Creating or Editing a Connection Pool

Use the General tab of the Connection Pool dialog box to create or edit a connection pool in the Physical layer of the Administration Tool. You must create a database object before you create a connection pool.

To create or edit a connection pool

In the Physical layer of the Administration Tool, do one of the following:
To create a connection pool, right-click a database and select New Object > Connection Pool from the shortcut menu.
To edit an existing connection pool, double-click the connection pool icon for the connection pool you want to edit.

The Connection Pool dialog box appears. Some of the fields are described in the following table.

Field	Comments
Name	The name for the connection pool. If you do not enter a name, the Administration Tool generates a name.
Permissions	Click to access the Permissions dialog box. You can use the Permissions dialog box to specify access permissions for individual users or groups. You can also set up a privileged group of users to have its own connection pool.
Call interface	The application program interface (API) with which to access the data source. Some databases may be accessed using native APIs, some use ODBC, and some work both ways.
Maximum connections	The maximum number of connections allowed for this connection pool.
Require fully qualified table names	When this option is selected, all requests sent from the connection pool use fully qualified names to query the underlying database. The fully qualified names are based on the physical object names in the repository. If you are querying the same tables from which the Physical layer metadata was imported, you can safely check the option. If you have migrated your repository from one physical database to another physical database that has different database and schema names, the fully qualified names would be invalid in the newly migrated database. In this case, if you do not select this option, the queries will succeed against the new database objects. For some data sources, fully qualified names might be safer because they guarantee that the queries are directed to the desired tables in the desired database. For example, if the RDBMS supports a master database concept, a query against a table named foo first looks for that table in the master database, and then looks for it in the specified database. If the table named foo exists in the master database, that table is queried, not the table named foo in the specified database.
Data source name	A data source name configured to access the database to which you want to connect. The data source name needs to contain valid logon information for a data source. If the information is invalid, the database logon specified in the DSN will fail.
Shared logon	Select the option Shared logon if you want all users whose queries use the connection pool to access the underlying database using the same user ID and password. If this option is selected, then all connections to the database that use the connection pool will use the user ID and password specified in the connection pool, even if the Siebel Analytics user has specified a database user ID and password in the DSN (or in the Siebel user configuration). If this option is not selected, connections through the connection pool use the database user ID and password specified in the DSN or in the Siebel user profile.
Enable connection pooling	Allows a single database connection to remain open for the specified time for use by future query requests. Connection pooling saves the overhead of opening and closing a new connection for every query. If you do not select this option, each query sent to the database opens a new connection.
Timeout (Minutes)	Specifies the amount of time, in minutes, that a connection to the data source will remain open after a request completes. During this time, new requests use this connection rather than open a new one (up to the number specified for the maximum connections). The time is reset after each completed connection request. If you set the timeout to 0, connection pooling is disabled; that is, each connection to the data source terminates immediately when the request completes. Any new connections either use another connection pool or open a new connection.
Execute queries asynchronously	Indicates whether the data source supports asynchronous queries. Asynchronous queries allow query cancellations to be sent to the database through the same connection while the query is executing. If this option is not selected, query cancellations might not propagate down to the underlying database.
Execute on Connect	Allows the Siebel Analytics Server administrator to specify a command to be executed each time a connection is made to the database. The command may be any command accepted by the database. For example, it could be used to turn on quoted identifiers. In a mainframe environment, it could be used to set the secondary authorization ID when connecting to DB2 to force a security exit to a mainframe security package such as RACF. This allows mainframe environments to maintain security in one central location.
Isolation level	For ODBC and DB2 gateways, sets the transaction isolation level on each connection handle to the back-end database.

Enter a name for the connection pool.
Select a call interface.

NOTE:  If the call interface is XML, the XML tab becomes active and options that do not apply to XML data sources will not be available.

Specify the maximum number of connections for the pool.
Select the option Require fully qualified table names if the database requires it.
Select or enter the data source name that the connection pool will access.

The drop-down list shows the User and System DSNs configured on your system.

If the connection pool uses a shared logon, select the option Shared logon and specify a user ID and password for the source.
To allow a single database connection to remain open for a specified number of minutes for use by future query requests, select the option Enable connection pooling.

NOTE:  If you do not select this option, each query sent to the database will open a new connection.

Enter the number of minutes that a connection to the data source will remain open after a request completes in the Timeout text box.
Select the option Execute queries asynchronously for data sources that support asynchronous queries.
To specify a command to be executed each time a connection is made to the database, enter the command string in the Execute on Connect text box.
Select an isolation level, if applicable.
(Optional) Enter a description of the connection pool.
Click Permissions to open the Permissions dialog box, where you can assign user or group permissions to the connection pool.

For information about assigning permissions to a connection pool, see Setting Permissions for Repository Objects.

Complete the XML tab if you specified XML as the data source.

Setting Properties for an XML Data Source

Use the XML tab of the Connection Pool dialog box to set additional properties for an XML data source.

NOTE:  The XML tab of the Physical Table dialog box provides the same functionality as the XML tab of the Connection Pool dialog box. However, the properties you set in the XML tab of the Physical Table dialog box override the corresponding settings in the Connection Pool dialog box.

To set connection properties

(Optional) If you specified a URL to access the data source, set the URL refresh interval:
Select a value from the drop-down list (Infinite, Days, Hours, Minutes or Seconds).
Specify a whole number as the numeric portion of the interval.

The refresh interval for XML data sources is analogous to setting cache persistence for database tables. The URL refresh interval is the time interval after which the XML data source is to be re-queried directly rather than using results in cache. The default setting is infinite, meaning the XML data source will never be refreshed.

(Optional) If you specified a URL to access the data source, set the URL loading time-out:
Select a value from the drop-down list (Infinite, Days, Hours, Minutes or Seconds).
Specify a whole number as the numeric portion of the of the interval.

The default time-out interval for queries (URL loading time-out) is 15 minutes.

To specify query output format settings

(Optional) For an XSLT file, enter the path to and name of the XSLT file in the XSLT File field, or use the Browse button.
(Optional) For an XPath expression, enter the XPath expression in the XPath Expression field, for example, //XML, or use the Browse button.

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