connection Pooling

­­­Connection Pooling
Default value of Max Pool size is 100.You can set that in SQL Connection String...e.g"Server=(local); ..........; Database=Northwind; Max Pool Size=45; Min Pool Size=10When a connection is opened and a pool is created, multiple connections are added to the pool to bring the connection count to the configured minimum level. Connections can be subsequently added to the pool up to the configured maximum pool count. When the maximum count is reached, new requests to open a connection are queued for a configurable duration.
Creating a Connection Pool
Each connection pool is associated with a specific connection string. By default, the connection pool is created when the first connection with a unique connection string connects to the database. The pool is populated with connections up to the minimum pool size.
Additional connections can be added until the pool reaches the maximum pool size.
The pool remains active as long as any connections remain open, either in the pool or used by an application with a reference to a Connection object that has an open connection.
If a new connection is opened and the connection string does not exactly match an existing pool, a new pool must be created. By using the same connection string, you can enhance the performance and scalability of your application.
In the following C# code fragment, three new DbConnection objects are created, but only two connection pools are required to manage them. Note that the connection strings for conn1 and conn2 differ by the values assigned for User ID, Password, and Min Pool Size connection string options.
DbProviderFactory Factory = DbProviderFactories.GetFactory("DDTek.Oracle");
DbConnection Conn1 = Factory.CreateConnection();
Conn1.ConnectionString = "Host=Accounting;Port=1521;User ID=scott;Password=tiger; " +
"Service Name=ORCL;Min Pool Size=50";

Conn1.Open();
// Pool A is created and filled with connections to the
// minimum pool size

DbConnection Conn2 = Factory.CreateConnection();
Conn2.ConnectionString =
"Host=Accounting;Port=1521;User ID=Jack;Password=quake; " +
"Service Name=ORCL;Min Pool Size=100";

Conn2.Open();
// Pool B is created because the connections strings differ

DbConnection Conn3 = Factory.CreateConnection();
Conn3.ConnectionString =
"Host=Accounting;Port=1521;User ID=scott;Password=tiger; " +
"Service Name=ORCL;Min Pool Size=50";

Conn3.Open();
// Conn3 is assigned an existing connection that was created in
// Pool A when the pool was created for Conn1

Once created, connection pools are not destroyed until the active process ends or the connection lifetime is exceeded. Maintenance of inactive or empty pools involves minimal system overhead.