MySQL is in this category. From a company-specific public Maven repository, if a database vendor makes one available. Oracle drivers are in this category.
Under some circumstances, the JVM engine that runs your EventFlow fragment can access the wrong data source if multiple drivers attempt to access the same data source. To avoid this potential problem, it is best for all applications that access a given data source to be in the same project in a StreamBase Studio workspace.
If your JDBC driver requires access to any supporting library files such as. The name you assign in your data source configuration file must follow the StreamBase identifier naming rules, as described in Identifier Naming Rules. You can use an encrypted password, as described on Encrypting Sensitive Configuration Data. Name the component in the General tab, and in the Data Source tab, identify the data source this table will use.
If no data sources appear in the drop-down list in this tab, this means you have not completely configured the server configuration file as described in the jdbcdatasource reference page, or that the configuration file is invalid. That is, for each query, drag a Query operator icon from the Palette view to the canvas. If automatic typechecking is enabled, StreamBase Studio performs typechecking at this point. Make sure the database server is running and is accepting connections.
If your Query operators need to share the same JDBC data source, you can configure connection pooling to do so. See the jdbcdatasource reference page for the available JDBC data source options. Different JDBC drivers allocate different sizes for column types. Very large column types such as the text column for the Microsoft JDBC driver can cause typecheck errors. By default, this parameter is set to As long as you specify a column size of or less, output tuple sizes will be acceptable. The SQL syntax depends on your database; here are three different examples of setting a column size to If the actual data in your columns exceeds the limit you set, the data will be truncated.
Set the maximum column size to a higher value. Now, compare the pooling results at each iteration checkpoint to the non-pooling results. Clearly, connection pooling represents a significant improvement in performance. Connection pooling provides a significant improvement on performance by reusing connections rather than creating a new connection for each connection request, without requiring changes in your JDBC application code.
Note that the time for the iteration pooled case is faster than the iteration pooled case. If the JIT compiler is disabled, the time for the iteration pooled case increases to 94 ms, while the time for the other pooled cases remains the same. Get Customer Support. Services Consulting Education Modernization Outsourcing. NET OData. Contact Us. Back to top. Figure 1. JDBC 3. This interface provides hooks that third-party vendors can use to implement pooling as a layer on top of their JDBC drivers.
This interface allows third-party vendors to implement pooling on top of their JDBC drivers. A PooledConnection object acts as a "factory" that creates Connection objects. A PooledConnection object maintains the physical connection to the database; the Connection object created by the PooledConnection object is simply a handle to the physical connection.
This interface is the entry point that allows interaction with their pooling module. The pooling vendor determines how these components will interact.
Usually, a connection cache module contains one or multiple classes. The connection cache module should have a class that implements the standard ConnectionEventListener interface.
The ConnectionEventListener interface receives ConnectionEvent objects from PooledConnection objects when a connection closes or a connection error occurs. When a connection, created by a PooledConnection, closes, the connection cache module returns the PooledConnection object to the cache.
This DataDirect Connect for. With stand alone Java programs where data source is needed it is more convenient to use connection pooling library like DBCP. In this example MySQL is used so mysql-connector-java Here we have a DataSource class that is a singleton class creating and returning the instance of dbcp2 BasicDataSource.
Another way of getting DataSource object is using c3p0 library.
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