| Oracle® Call Interface Programmer's Guide 10g Release 1 (10.1) Part Number B10779-01 |
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| Oracle® Call Interface Programmer's Guide 10g Release 1 (10.1) Part Number B10779-01 |
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View PDF |
This section describes the OCI connect, authorize, and initialize functions.
Initializes the connection pool.
sword OCIConnectionPoolCreate ( OCIEnv *envhp, OCIError *errhp, OCICPool *poolhp, OraText **poolName, sb4 *poolNameLen, CONST OraText *dblink, sb4 dblinkLen, ub4 connMin, ub4 connMax, ub4 connIncr, CONST OraText *poolUsername, sb4 poolUserLen, CONST OraText *poolPassword, sb4 poolPassLen, ub4 mode );
A pointer to the environment where the connection pool is to be created
An error handle which can be passed to OCIErrorGet().
An allocated pool handle.
The name of the connection pool connected to.
The length of the string pointed to by poolName.
Specifies the database (server) to connect to.
The length of the string pointed to by dblink.
Specifies the minimum number of connections in the connection pool. Valid values are 0 and higher.
These number of connections are opened to the server by OCIConnectionPoolCreate(). After this, connections are opened only when necessary. Generally, it should be set to the number of concurrent statements the application is planning or expecting to run.
Specifies the maximum number of connections that can be opened to the database. Once this value is reached, no more connections are opened. Valid values are 1 and higher.
Allows the application to set the next increment for connections to be opened to the database if the current number of connections are less than connMax. Valid values are 0 and higher.
Connection pooling requires an implicit primary session and this attribute provides a username for that session.
The length of poolUsername.
The password for the username poolUsername.
The length of poolPassword.
The modes supported are
Ordinarily, OCIConnectionPoolCreate() will be called with mode set to OCI_DEFAULT.
If you wish to change the pool attributes dynamically (for example: change the connMin, connMax, and connIncr parameters), call OCIConnectionPoolCreate() with mode set to OCI_CPOOL_REINITIALIZE. When this is done, the other parameters are ignored.
The OUT parameters poolName and poolNameLen will contain values to be used in subsequent OCIServerAttach() and OCILogon2() calls in place of the database name and the database name length arguments.
OCIConnectionPoolDestroy(), OCILogon2(), OCIServerAttach()
Destroys the connection pool.
sword OCIConnectionPoolDestroy ( OCICPool *poolhp, OCIError *errhp, ub4 mode );
A pool handle for which a pool has been created.
An error handle which can be passed to OCIErrorGet().
Currently, this function will support only the OCI_DEFAULT mode.
Creates and initializes an environment for OCI functions to work under.
sword OCIEnvCreate ( OCIEnv **envhpp, ub4 mode, CONST dvoid *ctxp, CONST dvoid *(*malocfp) (dvoid *ctxp, size_t size), CONST dvoid *(*ralocfp) (dvoid *ctxp, dvoid *memptr, size_t newsize), CONST void (*mfreefp) (dvoid *ctxp, dvoid *memptr)) size_t xtramemsz, dvoid **usrmempp );
A pointer to an environment handle whose encoding setting is specified by mode. The setting will be inherited by statement handles derived from envhpp.
Specifies initialization of the mode. Valid modes are:
OCIEnvCallback. The default behavior is to allow calling of OCIEnvCallback at the time that the environment is created.
Specifies the user-defined context for the memory callback routines.
Specifies the user-defined memory allocation function. If mode is OCI_THREADED, this memory allocation routine must be thread safe.
Specifies the context pointer for the user-defined memory allocation function.
Specifies the size of memory to be allocated by the user-defined memory allocation function.
Specifies the user-defined memory re-allocation function. If the mode is OCI_THREADED, this memory allocation routine must be thread safe.
Specifies the context pointer for the user-defined memory reallocation function.
Pointer to memory block.
Specifies the new size of memory to be allocated
Specifies the user-defined memory free function. If mode is OCI_THREADED, this memory free routine must be thread-safe.
Specifies the context pointer for the user-defined memory free function.
Pointer to memory to be freed
Specifies the amount of user memory to be allocated for the duration of the environment.
Returns a pointer to the user memory of size xtramemsz allocated by the call for the user.
This call creates an environment for all the OCI calls using the modes specified by the user.
This call returns an environment handle which is then used by the remaining OCI functions. There can be multiple environments in OCI, each with its own environment modes. This function also performs any process level initialization if required by any mode. For example if the user wants to initialize an environment as OCI_THREADED, then all libraries that are used by OCI are also initialized in the threaded mode.
If you are writing a DLL or a shared library using OCI library then this call should definitely be used instead of OCIInitialize() and OCIEnvInit() call.
| See Also:
For more information about the |
OCIHandleAlloc(),OCIHandleFree(),OCIEnvInit(), OCIEnvNlsCreate(),OCITerminate()
Allocates and initializes an OCI environment handle.
sword OCIEnvInit ( OCIEnv **envhpp, ub4 mode, size_t xtramemsz, dvoid **usrmempp );
A pointer to a handle to the environment.
Specifies initialization of an environment mode. Valid modes are:
In OCI_DEFAULT mode, the OCI library always mutexes handles. In OCI_NO_MUTEX modes, there is no mutexing in this environment.
In OCI_NO_MUTEX mode, all OCI calls done on the environment handle, or on handles derived from the environment handle, must be serialized. This can be done by either doing your own mutexing or by having only one thread operating on the environment handle.
The OCI_ENV_NO_UCB mode is used to suppress the calling of the dynamic callback routine OCIEnvCallback() at environment initialization time. The default behavior is to allow such a call to be made.
Specifies the amount of user memory to be allocated for the duration of the environment.
Returns a pointer to the user memory of size xtramemsz allocated by the call for the user for the duration of the environment.
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This call allocates and initializes an OCI environment handle. No changes are done to an already initialized handle. If OCI_ERROR or OCI_SUCCESS_WITH_INFO is returned, the environment handle can be used to obtain ORACLE specific errors and diagnostics.
This call is processed locally, without a server round trip.
The environment handle can be freed using OCIHandleFree().
| See Also:
For more information about the |
OCIHandleAlloc(),OCIHandleFree(),OCIEnvCreate(),OCITerminate()
Creates and initializes an environment handle for OCI functions to work under. It is an enhanced version of the OCIEnvCreate() function.
sword OCIEnvNlsCreate ( OCIEnv **envhpp, ub4 mode, dvoid *ctxp, dvoid *(*malocfp) (dvoid *ctxp, size_t size), dvoid *(*ralocfp) (dvoid *ctxp, dvoid *memptr, size_t newsize), void (*mfreefp) (dvoid *ctxp, dvoid *memptr)) size_t xtramemsz, dvoid **usrmempp ub2 charset, ub2 ncharset );
A pointer to an environment handle whose encoding setting is specified by mode. The setting will be inherited by statement handles derived from envhpp.
Specifies initialization of the mode. Valid modes are:
OCIEnvCallback. The default behavior is to allow calling of OCIEnvCallback at the time that the environment is created.
Specifies the user-defined context for the memory callback routines.
Specifies the user-defined memory allocation function. If mode is OCI_THREADED, this memory allocation routine must be thread-safe.
Specifies the context pointer for the user-defined memory allocation function.
Specifies the size of memory to be allocated by the user-defined memory allocation function.
Specifies the user-defined memory re-allocation function. If the mode is OCI_THREADED, this memory allocation routine must be thread safe.
Specifies the context pointer for the user-defined memory reallocation function.
Pointer to memory block.
Specifies the new size of memory to be allocated
Specifies the user-defined memory free function. If mode is OCI_THREADED, this memory free routine must be thread-safe.
Specifies the context pointer for the user-defined memory free function.
Pointer to memory to be freed
Specifies the amount of user memory to be allocated for the duration of the environment.
Returns a pointer to the user memory of size xtramemsz allocated by the call for the user.
The client-side character set for the current environment handle. If it is 0, the NLS_LANG setting is used. OCI_UTF16ID is a valid setting; it is used by the metadata and the CHAR data.
The client-side national character set for the current environment handle. If it is 0, NLS_NCHAR setting is used. OCI_UTF16ID is a valid setting; it is used by the NCHAR data.
OCI_SUCCESS - environment handle has been successfully created.
OCI_ERROR - an error occurred.
This call creates an environment for all the OCI calls using the modes specified by the user.
After using OCIEnvNlsCreate() to create the environment handle, the actual lengths and returned lengths of bind and define handles are always in number of bytes. This applies to the following calls:
This function enables you to set charset and ncharset ids at environment creation time. It is an enhanced version of the OCIEnvCreate() function.
This function sets nonzero charset and ncharset as client side database and national character sets, replacing the ones specified by NLS_LANG and NLS_NCHAR. When charset and ncharset are 0, it behaves exactly the same as OCIEnvCreate(). Specifically, charset controls the encoding for metadata and data with implicit form attribute and ncharset controls the encoding for data with SQLCS_NCHAR form attribute.
Although OCI_UTF16ID can be set by OCIEnvNlsCreate(), it cannot be set in NLS_LANG or NLS_NCHAR. To access the character set ids in NLS_LANG and NLS_NCHAR, use OCINlsEnvironmentVariableGet().
This call returns an environment handle which is then used by the remaining OCI functions. There can be multiple environments in OCI, each with its own environment modes. This function also performs any process level initialization if required by any mode. For example if the user wants to initialize an environment as OCI_THREADED, then all libraries that are used by OCI are also initialized in the threaded mode.
If you are writing a DLL or a shared library using OCI library then this call should definitely be used instead of OCIInitialize() and OCIEnvInit() calls.
| See Also:
For more information about the |
OCIHandleAlloc(), OCIHandleFree(), OCITerminate(), OCINlsEnvironmentVariableGet()
Initializes the OCI process environment.
sword OCIInitialize ( ub4 mode, CONST dvoid *ctxp, CONST dvoid *(*malocfp) (/* dvoid *ctxp, size_t size _*/), CONST dvoid *(*ralocfp) (/*_ dvoid *ctxp, dvoid *memptr, size_t newsize _*/), CONST void (*mfreefp) (/*_ dvoid *ctxp, dvoid *memptr _*/));
Specifies initialization of the mode. The valid modes are:
User defined context for the memory call back routines.
User-defined memory allocation function. If mode is OCI_THREADED, this memory allocation routine must be thread safe.
mode is OCI_THREADED, this memory allocation routine must be thread safe.User-defined memory free function. If mode is OCI_THREADED, this memory free routine must be thread safe.
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This call initializes the OCI process environment. OCIInitialize() must be invoked before any other OCI call.
This function provides the ability for the application to define its own memory management functions through callbacks. If the application has defined such functions (that is, memory allocation, memory re-allocation, memory free), they should be registered using the callback parameters in this function.
These memory callbacks are optional. If the application passes NULL values for the memory callbacks in this function, the default process memory allocation mechanism is used.
See Also:
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The following statement shows an example of how to call OCIInitialize() in both threaded and object mode, with no user-defined memory functions:
OCIInitialize((ub4) OCI_THREADED | OCI_OBJECT, (dvoid *)0, (dvoid * (*)()) 0, (dvoid * (*)()) 0, (void (*)()) 0 );
OCIHandleAlloc(),OCIHandleFree(),OCIEnvCreate(),OCIEnvInit(), OCITerminate()
This function is used to release a session that was retrieved using OCILogon2() or OCILogon().
sword OCILogoff ( OCISvcCtx *svchp OCIError *errhp );
The service context handle which was used in the call to OCILogon() or OCILogon2().
An error handle you can pass to OCIErrorGet() for diagnostic information in the event of an error.
This function is used to release a session that was retrieved using OCILogon2() or OCILogon(). If OCILogon() was used, then this function terminates the connection and session. If OCILogon2() was used, then the exact behavior of this call is determined by the mode in which the corresponding OCILogon2() function was called. In the default case, it will close the session/connection. For connection pooling, it closes the session and returns the connection to the pool. For session pooling, it returns the session/connection pair to the pool.
| See Also:
For more information on logging on and off in an application, refer to the section "Application Initialization, Connection, and Session Creation". |
This function is used to create a simple logon session.
sword OCILogon ( OCIEnv *envhp, OCIError *errhp, OCISvcCtx **svchp, CONST OraText *username, ub4 uname_len, CONST OraText *password, ub4 passwd_len, CONST OraText *dbname, ub4 dbname_len );
The OCI environment handle.
An error handle you can pass to OCIErrorGet() for diagnostic information in the event of an error.
The service context pointer.
The username. Must be in the encoding specified by the charset parameter of a previous call to OCIEnvNlsCreate().
The length of username, in number of bytes, regardless of the encoding.
The user's password. Must be in the encoding specified by the charset parameter of a previous call to OCIEnvNlsCreate().
The length of password, in number of bytes, regardless of the encoding.
The name of the database to connect to. Must be in the encoding specified by the charset parameter of a previous call to OCIEnvNlsCreate().
The length of dbname, in number of bytes, regardless of the encoding.
This function is used to create a simple logon session for an application.
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Note: Users requiring more complex sessions, such as TP monitor applications, should refer to the section "Application Initialization, Connection, and Session Creation". |
This call allocates the service context handles that are passed to it. This call also implicitly allocates server and user session handles associated with the session. These handles can be retrieved by calling OCIAttrGet() on the service context handle.
Get a session. This session may be a new one with a new underlying connection, or one that is started over a virtual connection from an existing connection pool, or one from an existing session pool. The mode that the function is called with determines its behavior.
sword OCILogon2 ( OCIEnv *envhp, OCIError *errhp, OCISvcCtx **svchp, CONST OraText *username, ub4 uname_len, CONST OraText *password, ub4 passwd_len, CONST OraText *dbname, ub4 dbname_len ); ub4 mode );
The OCI environment handle. For connection pooling and session pooling, this must be the one that the respective pool was created in.
An error handle you can pass to OCIErrorGet() for diagnostic information in the event of an error.
Address of an OCI service context pointer. This will be filled with a server and session handle.
In the default case, a new session and server handle will be allocated, the connection and session will be started, and the service context will be populated with these handles.
For connection pooling, a new session handle will be allocated, and the session will be started over a virtual connection from the connection pool.
For session pooling, the service context will be populated with an existing session/server handle pair from the session pool.
Note that the user must not change any attributes of the server and user/session handles associated with the service context pointer. Doing so will result in an error being returned by the OCIAttrSet() call.
The only attribute of the service context that can be altered is OCI_ATTR_STMTCACHESIZE.
The username used to authenticate the session. Must be in the encoding specified by the charset parameter of a previous call to OCIEnvNlsCreate().
The length of username, in number of bytes, regardless of the encoding.
The user's password. For connection pooling, if this parameter is NULL then OCILogon2() assumes that the logon is for a proxy user. It implicitly creates a proxy connection in such a case, using the pool user to authenticate the proxy user. Must be in the encoding specified by the charset parameter of a previous call to OCIEnvNlsCreate().
The length of password, in number of bytes, regardless of the encoding.
For the default case, this indicates the connect string to use to connect to the Oracle database server.
For connection pooling, it indicates the connection pool to retrieve the virtual connection from, in order to start up the session. This value is returned by the OCIConnectionPoolCreate() call.
For session pooling, it indicates the pool to get the session from. It is returned by the OCISessionPoolCreate() call.
Must be in the encoding specified by the charset parameter of a previous call to OCIEnvNlsCreate().
The length of dbname. For session pooling and connection pooling, this value is returned by the OCISessionPoolCreate() or OCIConnectionPoolCreate() call respectively.
The values accepted are
For the default (non-pooling case), the following modes are valid:
OCI_DEFAULT - Equivalent to calling OCILogon().
OCI_LOGON2_STMTCACHE - Enable statement caching.
For connection pooling, the following modes are valid:
OCI_LOGON2_CPOOL or OCI_CPOOL - This must be set in order to use connection pooling.
OCI_LOGON2_STMTCACHE - Enable statement caching.
In order to use proxy authentication for connection pooling, the password must be set to NULL. The user will then be given a session that is authenticated by the username provided in the OCILogon2() call, through the proxy credentials supplied in the OCIConnectionPoolCreate() call.
For session pooling, the following modes are valid:
OCI_LOGON2_SPOOL - This must be set in order to use session pooling.
OCI_LOGON2_STMTCACHE - Enable statement caching.
OCI_LOGON2_PROXY - Use proxy authentication.The user is given a session that is authenticated by the username provided in the OCILogon2() call, through the proxy credentials supplied in the OCISessionPoolCreate() call.
None.
OCILogon(),OCILogoff(),OCISessionGet(),OCISessionRelease()
Creates an access path to a data source for OCI operations.
sword OCIServerAttach ( OCIServer *srvhp, OCIError *errhp, CONST text *dblink, sb4 dblink_len, ub4 mode );
An uninitialized server handle, which gets initialized by this call. Passing in an initialized server handle causes an error.
An error handle you can pass to OCIErrorGet() for diagnostic information in the event of an error.
Specifies the database server to use. This parameter points to a character string which specifies a connect string or a service point. If the connect string is NULL, then this call attaches to the default host. The string itself could be in UTF-16 or not, depending on mode or the setting in application's environment handle. The length of dblink is specified in dblink_len. The dblink pointer may be freed by the caller on return.
The name of the connection pool to connect to when mode = OCI_CPOOL. This must be the same as the poolName parameter of the connection pool created by OCIConnectionPoolCreate(). Must be in the encoding specified by the charset parameter of a previous call to OCIEnvNlsCreate().
The length of the string pointed to by dblink. For a valid connect string name or alias, dblink_len must be nonzero. Its value is in number of bytes.
The length of poolName, in number of bytes, regardless of the encoding, when mode = OCI_CPOOL.
Specifies the various modes of operation. The valid modes are:
Since an attached server handle can be set for any connection session handle, the mode value here does not contribute to any session handle.
This call is used to create an association between an OCI application and a particular server.
This call assumes that OCIConnectionPoolCreate() has already been called, giving poolName, when connection pooling is in effect.
This call initializes a server context handle, which must have been previously allocated with a call to OCIHandleAlloc(). The server context handle initialized by this call can be associated with a service context through a call to OCIAttrSet(). Once that association has been made, OCI operations can be performed against the server.
If an application is operating against multiple servers, multiple server context handles can be maintained. OCI operations are performed against whichever server context is currently associated with the service context.
When OCIServerAttach() is successfully completed, an Oracle shadow process is started. OCISessionEnd() and OCIServerDetach() should be called to clean up the Oracle shadow process. Otherwise, the shadow processes accumulate and cause the Unix system to run out of processes. If the database is restarted and there are not enough processes, the database may not startup.
The following example demonstrates the use of OCIServerAttach(). This code segment allocates the server handle, makes the attach call, allocates the service context handle, and then sets the server context into it.
OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &srvhp, (ub4) OCI_HTYPE_SERVER, 0, (dvoid **) 0); OCIServerAttach( srvhp, errhp, (text *) 0, (sb4) 0, (ub4) OCI_DEFAULT); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &svchp, (ub4) OCI_HTYPE_SVCCTX, 0, (dvoid **) 0); /* set attribute server context in the service context */ OCIAttrSet( (dvoid *) svchp, (ub4) OCI_HTYPE_SVCCTX, (dvoid *) srvhp, (ub4) 0, (ub4) OCI_ATTR_SERVER, (OCIError *) errhp);
Deletes an access to a data source for OCI operations.
sword OCIServerDetach ( OCIServer *srvhp, OCIError *errhp, ub4 mode );
A handle to an initialized server context, which gets reset to uninitialized state. The handle is not de-allocated.
An error handle you can pass to OCIErrorGet() for diagnostic information in the event of an error.
Specifies the various modes of operation. The only valid mode is OCI_DEFAULT for the default mode.
This call deletes an access to data source for OCI operations, which was established by a call to OCIServerAttach().
Creates a user session and begins a user session for a given server.
sword OCISessionBegin ( OCISvcCtx *svchp, OCIError *errhp, OCISession *usrhp, ub4 credt, ub4 mode );
A handle to a service context. There must be a valid server handle set in svchp.
An error handle you can pass to OCIErrorGet() for diagnostic information in the event of an error.
A handle to an user session context, which is initialized by this call.
Specifies the type of credentials to use for establishing the user session. Valid values for credt are:
Specifies the various modes of operation. Valid modes are:
svchp. For encoding, the server handle uses the setting in the environment handle.The OCISessionBegin() call is used to authenticate a user against the server set in the service context handle.
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Note: Check for any errors returned when trying to start a session. For example, if the password for the account has expired, an ORA-28001 error is returned. |
For release 8.1 or later, OCISessionBegin() must be called for any given server handle before requests can be made against it. OCISessionBegin() only supports authenticating the user for access to the Oracle server specified by the server handle in the service context. In other words, after OCIServerAttach() is called to initialize a server handle, OCISessionBegin() must be called to authenticate the user for that given server.
When using Unicode, when the mode or the environment handle has the appropriate setting, the username and password that have been set in the session handle usrhp should already be in Unicode. Before calling this function to start a session with a username and password, you must have called OCIAttrSet() to set these two Unicode strings into the session handle with corresponding length in bytes, because OCIAttrSet() only takes dvoid pointers. The string buffers then will be interpreted by OCISessionBegin().
When OCISessionBegin() is called for the first time for a given server handle, the user session may not be created in migratable (OCI_MIGRATE) mode.
After OCISessionBegin() has been called for a server handle, the application may call OCISessionBegin() again to initialize another user session handle with different (or the same) credentials and different (or the same) operation modes. If an application wants to authenticate a user in OCI_MIGRATE mode, the service handle must already be associated with a non-migratable user handle. The user ID of that user handle becomes the ownership ID of the migratable user session. Every migratable session must have a non-migratable parent session.
If the OCI_MIGRATE mode is not specified, then the user session context can only be used with the same server handle set in svchp. If OCI_MIGRATE mode is specified, then the user authentication may be set with different server handles. However, the user session context may only be used with server handles which resolve to the same database instance. Security checking is done during session switching. A session can migrate to another process only if there is a non-migratable session currently connected to that process whose userid is the same as that of the creator's userid or its own userid.
OCI_SYSDBA, OCI_SYSOPER, and OCI_PRELIM_AUTH may only be used with a primary user session context.
To provide credentials for a call to OCISessionBegin(), one of two methods are supported. The first is to provide a valid username and password pair for database authentication in the user session handle passed to OCISessionBegin(). This involves using OCIAttrSet() to set the OCI_ATTR_USERNAME and OCI_ATTR_PASSWORD attributes on the user session handle. Then OCISessionBegin() is called with OCI_CRED_RDBMS.
The second type of credentials supported are external credentials. No attributes need to be set on the user session handle before calling OCISessionBegin(). The credential type is OCI_CRED_EXT. This is equivalent to the Oracle7 'connect /' syntax. If values have been set for OCI_ATTR_USERNAME and OCI_ATTR_PASSWORD, then these are ignored if OCI_CRED_EXT is used.
Another way of setting credentials is to use the session Id of an already authenticated user with the OCI_MIGSESSION attribute. This Id can be extracted from the session handle of an authenticated user using the OCIAttrGet() call.
The following example demonstrates the use of OCISessionBegin(). This code segment allocates the user session handle, sets the username and password attributes, calls OCISessionBegin(), and then sets the user session into the service context.
/* allocate a user session handle */ OCIHandleAlloc((dvoid *)envhp, (dvoid **)&usrhp, (ub4) OCI_HTYPE_SESSION, (size_t) 0, (dvoid **) 0); OCIAttrSet((dvoid *)usrhp, (ub4)OCI_HTYPE_SESSION, (dvoid *)"hr", (ub4)strlen("hr"), OCI_ATTR_USERNAME, errhp); OCIAttrSet((dvoid *)usrhp, (ub4)OCI_HTYPE_SESSION, (dvoid *)"hr", (ub4)strlen("hr"), OCI_ATTR_PASSWORD, errhp); checkerr(errhp, OCISessionBegin (svchp, errhp, usrhp, OCI_CRED_RDBMS, OCI_DEFAULT)); OCIAttrSet((dvoid *)svchp, (ub4)OCI_HTYPE_SVCCTX, (dvoid *)usrhp, (ub4)0, OCI_ATTR_SESSION, errhp);
Terminates a user session context created by OCISessionBegin()
sword OCISessionEnd ( OCISvcCtx *svchp, OCIError *errhp, OCISession *usrhp, ub4 mode );
The service context handle. There must be a valid server handle and user session handle associated with svchp.
An error handle you can pass to OCIErrorGet() for diagnostic information in the event of an error.
De-authenticate this user. If this parameter is passed as NULL, the user in the service context handle is de-authenticated.
The only valid mode is OCI_DEFAULT.
The user security context associated with the service context is invalidated by this call. Storage for the user session context is not freed. The transaction specified by the service context is implicitly committed. The transaction handle, if explicitly allocated, may be freed if not being used. Resources allocated on the server for this user are freed. The user session handle may be reused in a new call to OCISessionBegin().
Get a session. This session may be a new one with a new underlying connection, or one that is started over a virtual connection from an existing connection pool, or one from an existing session pool. The mode that the function is called with determines its behavior.
sword OCISessionGet ( OCIenv *envhp, OCIError *errhp, OCISvcCtx **svchp, OCIAuthInfo *authInfop, OraText *dbName, ub4 dbName_len, CONST OraText *tagInfo, ub4 tagInfo_len, OraText **retTagInfo, ub4 *retTagInfo_len, boolean *found, ub4 mode );
OCI environment handle. For connection pooling and session pooling, this should be the one that the respective pool was created in.
OCI error handle.
Address of an OCI service context pointer. This will be filled with a server and session handle.
In the default case, a new session and server handle will be allocated, the connection and session will be started, and the service context will be populated with these handles.
For connection pooling, a new session handle will be allocated, and the session will be started over a virtual connection from the connection pool.
For session pooling, the service context will be populated with an existing session and server handle pair from the session pool.
Do not change any attributes of the server and user and session handles associated with the service context pointer. Doing so will result in an error being returned by the OCIAttrSet() call.
The only attribute of the service context that can be altered is OCI_ATTR_STMTCACHESIZE.
Authentication Information handle to be used while getting the session.
In the default and connection pooling cases, this handle can take all the attributes of the session handle.
For session pooling, the authentication information handle is considered only if the session pool mode is not set to OCI_SPC_HOMOGENEOUS. In this case, this handle can have the following attributes set:
OCI_ATTR_USERNAME
OCI_ATTR_PASSWORD
OCI_ATTR_INITIAL_CLIENT_ROLES
Please refer to user handle attributes for more information.
For the default case, this indicates the connect string to use to connect to the Oracle database server.
For connection pooling, it indicates the connection pool to retrieve the virtual connection from, in order to start up the session. This value is returned by the OCIConnectionPoolCreate() call.
For session pooling, it indicates the pool to get the session from. It is returned by the OCISessionPoolCreate() call.
The length of dbName. For session pooling and connection pooling, this value is returned by the call to OCISessionPoolCreate() or OCIConnectionPoolCreate(), respectively.
This parameter is only used for session pooling.
This indicates the type of session that the user wants. If the user wants a default session, the user must set this to NULL. Please refer to the Comments for a detailed usage of this parameter.
The length in bytes, of tagInfo. Used for session pooling only.
This parameter is only used for session pooling. This indicates the type of session that is returned to the user. Please refer to the Comments for a detailed usage of this parameter.
The length in bytes, of retTagInfo. Used for session pooling only.
This parameter is only used for session pooling. If the type of session that the user requested was returned (that is, the value of tagInfo and retTagInfo is the same), then found is set to TRUE, else, found is set to FALSE.
The valid modes are
In the default (non-pooling) case, the following modes are valid:
OCI_SESSGET_STMTCACHE - This will enable statement caching in the session.
OCI_SESSGET_CREDEXT - This will return a session authenticated with external credentials.
For connection pooling, the following modes are valid:
OCI_SESSGET_CPOOL - This must be set in order to use connection pooling.
OCI_SESSGET_STMTCACHE - This will enable statement caching in the session.
OCI_SESSGET_CREDPROXY - This will return a proxy session. The user is given a session that is authenticated by the username provided in the OCISessionGet() call, through the proxy credentials supplied in the OCIConnectionPoolCreate() call.
OCI_SESSGET_CREDEXT - This will return a session authenticated with external credentials.
For session pooling, the following modes are valid:
OCI_SESSGET_SPOOL - This must be set in order to use session pooling.
OCI_SESSGET_CREDPROXY - In this case, the user is given a session that is authenticated by the username provided in the OCISessionGet() call, through the proxy credentials supplied in the OCISessionPoolCreate() call.
OCI_SESSGET_SPOOL_MATCHANY - This refers to the tagging behavior. If this mode is set, then a session which has a different tag than what was asked for, may be returned. Please refer to the Comments section.
The tags provide a way for users to customize sessions in the pool. A client can get a default or untagged session from a pool, set certain attributes on the session (such as Globalization settings), and return the session to the pool, labeling it with an appropriate tag in the OCISessionRelease() call.
The user, or some other user, can request for a session with the same attributes, and can do so by providing the same tag in the OCISessionGet() call.
If a user asks for a session with tag 'A', and a matching session is not available, an appropriately authenticated untagged session (session with a NULL tag) will be returned, if such a session is free. If even an untagged session is not free and OCI_SESSGET_SPOOL_MATCHANY has been specified, then an appropriately authenticated session with a different tag will be returned. If OCI_SESSGET_SPOOL_MATCHANY is not set, then a session with a different tag is never returned.
OCISessionRelease(), OCISessionPoolCreate(), OCISessionPoolDestroy()
Initializes a session pool. It starts up sessMin number of sessions and connections to the database. Before making this call, make a call to OCIHandleAlloc() to allocate memory for the session pool handle.
sword OCISessionPoolCreate ( OCIEnv *envhp, OCIError *errhp, OCISPool *spoolhp, OraText **poolName, ub4 *poolNameLen, CONST OraText *connStr, ub4 connStrLen, ub4 sessMin, ub4 sessMax, ub4 sessIncr, OraText *userid, ub4 useridLen, OraText *password, ub4 passwordLen, ub4 mode );
A pointer to the environment handle in which the session pool needs to be created.
An error handle which can be passed to OCIErrorGet().
A pointer to the session pool handle that is initialized.
The name of the session pool returned. It is unique across all session pools in an environment. This value must be passed to the OCISessionGet() call.
Length of poolName in bytes.
The TNS alias of the database to connect to.
The length of connStr in bytes.
Specifies the minimum number of sessions in the session pool.
This number of sessions are started by OCISessionPoolCreate(). After this, sessions are opened only when necessary.
This value is used when mode is set to OCI_SPC_HOMOGENEOUS. In all other cases it is ignored.
Specifies the maximum number of sessions that can be opened in the session pool. Once this value is reached, no more sessions are opened. The valid values are 1 and higher.
Allows applications to set the next increment for sessions to be started if the current number of sessions are less than sessMax. The valid values are 0 and higher.
sessMin + sessIncr cannot be more than sessMax.
Specifies the userid with which to start up the sessions.
| See Also:
For more information about this parameter see "Authentication Note." |
Length of the userid in bytes.
The password for the corresponding userid.
The length of the password in bytes.
The modes supported are
sessMin, sessMax, and sessIncr parameters), call OCISessionPoolCreate() with mode set to OCI_SPC_REINITIALIZE. When mode is set to OCI_SPC_REINITIALIZE, then connStr, userid, and password will be ignored.OCI_SPC_STMTCACHE - an OCI statement cache will be created for the session pool. If the pool is not created with OCI statement caching turned on, server-side statement caching will automatically be used. Please note that in general, client- side statement caching will give better performance.
OCISessionPoolCreate(). The authentication handle (parameter authInfo) passed into OCISessionGet() is ignored in this case. Moreover, the sessMin and the SessIncr values are considered only in this case. No proxy session can be created in this mode.Please note that a session pool may contain two types of connections to the database: direct connections and proxy connections. To make a proxy connection, a user must have Connect through Proxy privilege.
When the session pool is created, the userid and password may or may not be specified. If these values are NULL, no proxy connections can exist in this pool. If mode is set to OCI_SPC_HOMOGENEOUS, no proxy connection can exist.
A userid and password pair may also be specified through the authentication handle in the OCISessionGet() call. If this call is made with mode set to OCI_SESSGET_CREDPROXY, then the user is given a session that is authenticated by the userid provided in the OCISessionGet() call, through the proxy credentials supplied in the OCISessionPoolCreate() call. In this case, the password in the OCISessionGet() call is ignored.
If OCISessionGet() is called with mode not set to OCI_SESSGET_CREDPROXY, then the user gets a direct session which is authenticated by the credentials provided in the OCISessionGet() call. If none have been provided in this call, the user gets a session authenticated by the credentials in the OCISessionPoolCreate() call.
OCISessionRelease(), OCISessionGet(), OCISessionPoolDestroy()
Destroys a session pool.
sword OCISessionPoolDestroy ( OCISPool *spoolhp, OCIError *errhp, ub4 mode );
The session pool handle for the session pool to be destroyed.
An error handle which can be passed to OCIErrorGet().
Currently, OCISessionPoolDestroy() will support modes OCI_DEFAULT and OCI_SPD_FORCE.
If this call is made with mode set to OCI_SPD_FORCE, and there are active sessions in the pool, the sessions will be closed and the pool will be destroyed. However, if this mode is not set, and there are busy sessions in the pool, an error will be returned.
OCISessionPoolCreate(), OCISessionRelease(), OCISessionGet()
This function is used to release a session that was retrieved using OCISessionGet(). The exact behavior of this call is determined by the mode in which the corresponding OCISessionGet() function was called. In the default case, it will close the session/connection. For connection pooling, it closes the session and returns the connection to the pool. For session pooling, it returns the session/connection pair to the pool.
sword OCISessionRelease ( OCISvcCtx *svchp, OCIError *errhp, OraText *tag, ub4 tag_len, ub4 mode );
The service context that was populated during the corresponding OCISessionGet() call.
In the default case, the session and connection associated with this handle will be closed.
In the connection pooling case, the session will be closed and the connection released to the pool.
For session pooling, the session/connection pair associated with this service context will be released to the pool.
The OCI error handle.
This parameter is only used for session pooling.
This parameter will be ignored unless mode OCI_SESSRLS_RETAG is specified. In this case, the session is labelled with this tag and returned to the pool. If this is NULL, then the session is not tagged.
This parameter is only used for session pooling.
Length of the tag. This is ignored unless mode OCI_SESSRLS_RETAG is set.
The supported modes are
For the default case and for connection pooling, only OCI_DEFAULT can be used.
OCI_SESSRLS_DROPSESS and OCI_SESSRLS_RETAG are only used for session pooling.
When OCI_SESSRLS_DROPSESS is specified, the session will be removed from the session pool.
If and only if OCI_SESSRLS_RETAG is set, will the tag on the session be altered. If this mode is not set, the tag and tag_len parameters will be ignored.
In this call the user be careful to pass in the correct tag. If a default session is requested and the user sets certain properties on this session (probably through an ALTER SESSION command), then the user must label this session appropriately by tagging it as such.
If on the other hand, the user requested a tagged session and got one, and has changed the properties on the session, then the user must pass in a different tag if appropriate.
For the correct working of the session pool layer the application developer must be very careful to pass in the correct tag to the OCISessionGet() and OCISessionRelease() calls.
OCISessionGet(), OCISessionPoolCreate(), OCISessionPoolDestroy(),OCILogon2()
Detaches the process from the shared memory subsystem and releases the shared memory.
sword OCITerminate ( ub4 mode);
Call-specific mode. Valid value:
OCITerminate() should be called only once for each process and is the counterpart of OCIInitialize() call. The call will try to detach the process from the shared memory subsystem and shut it down. It also performs additional process cleanup operations. When two or more processes connecting to the same shared memory are calling OCITerminate() simultaneously, the fastest one will release the shared memory subsystem completely and the slower ones will have to terminate.
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