Connection Pool Class

The ConnectionPool class represents a pool of connections for a specific database.

Table 10-10 Summary of ConnectionPool Methods

Method	Summary
createConnection()	Create a pooled connection.
createProxyConnection()	Create a proxy connection.
getBusyConnections()	Return the number of busy connections in the connection pool.
getIncrConnections()	Return the number of incremental connections in the connection pool.
getMaxConnections()	Return the maximum number of connections in the connection pool.
getMinConnections()	Return the minimum number of connections in the connection pool.
getOpenConnections()	Return the number of open connections in the connection pool.
getPoolName()	Return the name of the connection pool.
getStmtCacheSize()	Retrieves the size of the statement cache.
getTimeOut()	Return the time out period for a connection in the connection pool.
setErrorOnBusy()	Specify that a `SQLException` should be generated when all connections in the connection pool are busy and no further connections can be opened.
setPoolSize()	Set the minimum, maximum, and incremental number of pooled connections for the connection pool.
setStmtCacheSize()	Retrieves the size of the statement cache.
setTimeOut()	Set the time out period, in seconds, for a connection in the connection pool.
terminateConnection()	Destroy the connection.

createConnection()

Creates a pooled connection.

Syntax	Description
Connection* createConnection( const string &userName, const string &password);	Creates a pooled connection.
Connection* createConnection( const UString &username, const UString &password);	Creates a globalization enabled pooled connection.

Parameter	Description
userName	The name of the user with which to connect.
password	The password of the user.

createProxyConnection()

Creates a proxy connection from the connection pool.

Syntax	Description
Connection* createProxyConnection( const string &name, Connection::ProxyType proxyType=Connection::PROXY_DEFAULT);	Creates a proxy connection.
Connection* createProxyConnection( const UString &name, Connection::ProxyType proxyType=Connection::PROXY_DEFAULT);	Creates a globalization enabled proxy connection.
Connection* createProxyConnection( const string &name, string roles[], int numRoles, Connection::ProxyType proxyType=Connection::PROXY_DEFAULT);	Creates a proxy connection for several roles.
Connection* createProxyConnection( const UString &name, std::string roles[], unsigned int numRoles, Connection::ProxyType proxyType=Connection::PROXY_DEFAULT);	Creates a globalization enabled proxy connection for several roles.

Parameter	Description
name	The user name to connect with.
roles	The roles to activate on the database server.
numolesR	The number of roles to activate on the database server.
numolesR	The type of proxy authentication to perform. Valid values are: `PROXY_DEFAULT` representing a database user name. `PROXY_EXTERNAL_AUTH` representing an external user name.

getBusyConnections()

Returns the number of busy connections in the connection pool.

Syntax

unsigned int getBusyConnections() const;

getIncrConnections()

Returns the number of incremental connections in the connection pool.

Syntax

unsigned int getIncrConnections() const;

getMaxConnections()

Returns the maximum number of connections in the connection pool.

Syntax

unsigned int getMaxConnections() const;

getMinConnections()

Returns the minimum number of connections in the connection pool.

Syntax

unsigned int getMinConnections() const;

getOpenConnections()

Returns the number of open connections in the connection pool.

Syntax

unsigned int getOpenConnections() const;

getPoolName()

Returns the name of the connection pool.

Syntax

string getPoolName() const;

getStmtCacheSize()

Retrieves the size of the statement cache.

Syntax

unsigned int getStmtCacheSize() const;

getTimeOut()

Returns the time out period of a connection in the connection pool.

Syntax

unsigned int getTimeOut() const;

setErrorOnBusy()

Specifies that a SQLException is to be generated when all connections in the connection pool are busy and no further connections can be opened.

Syntax

void setErrorOnBusy();

setPoolSize()

Sets the minimum, maximum, and incremental number of pooled connections for the connection pool.

Syntax

void setPoolSize(
   unsigned int minConn = 0,
   unsigned int maxConn = 1,
   unsigned int incrConn = 1);

Parameter	Description
minConn	The minimum number of connections for the connection pool.
maxConn	The maximum number of connections for the connection pool.
incrConn	The incremental number of connections for the connection pool.

setStmtCacheSize()

Enables or disables statement caching.

A nonzero value will enable statement caching, with a cache of specified size.
A zero value will disable caching.

Syntax

void setStmtCacheSize(
   unsigned int size);

Parameter	Description
size	The size of the statement cache.

setTimeOut()

Sets the time out period for a connection in the connection pool. OCCI will terminate any connections related to this connection pool that have been idle for longer than the time out period specified.

Syntax

void setTimeOut(
   unsigned int connTimeOut = 0);

Parameter	Description
connTimeOut	The timeout period in number of seconds.

terminateConnection()

Terminates the pooled connection or proxy connection.

Syntax

void terminateConnection(
   Connection *connection);

Parameter	Description
connection	The pooled connection or proxy connection to terminate.