The following connection option descriptions are listed alphabetically by the GUI name that appears on the driver Setup dialog box. The connection string attribute name, along with its short name, is listed immediately underneath the GUI name.
In most cases, the GUI name and the attribute name are the same; however, some exceptions exist. If you need to look up an option by its connection string attribute name, please refer to the alphabetical table of connection string attribute names.
Also, a few connection string attributes, for example, Password, do not have equivalent options that appear on the GUI. They are in the list of descriptions alphabetically by their attribute names.
Table 20-1 lists the connection string attributes supported by the Greenplum Wire Protocol driver.
A list of alternate database servers to which the driver tries to connect if the primary database server is unavailable. Specifying a value for this option enables connection failover for the driver. The value you specify must be in the form of a string that defines the physical location of each alternate server. All of the other required connection information for each alternate server is the same as what is defined for the primary server connection.
(HostName=
hostvalue:PortNumber=
portvalue:Database
=databasevalue[, . . .]
)
If set to 0 (Disabled), the driver does not work with multi-threaded applications. If using the driver with single-threaded applications, this value avoids additional processing required for ODBC thread-safety standards.
If set to 1 (Enabled), the state of connections removed from the connection pool for reuse by an application is reset to the initial configuration of the connection. Resetting the state can negatively impact performance because additional commands must be sent over the network to the server to reset the state of the connection.
where x is a positive integer from 1 to 65535.
If set to x, the driver retries connection attempts the specified number of times. If a connection is not established during the retry attempts, the driver returns an error that is generated by the last server to which it tried to connect.
where x is a positive integer from 1 to 65535.
If set to x, the driver waits the specified number of seconds between connection retry attempts.
where string is the name of a data source.
where database_name is the name of a valid database.
An optional long description of a data source. This description is not used as a runtime connection attribute, but does appear in the ODBC.INI section of the Registry and in the odbc.ini file.
where string is a description of a data source.
If set to 0 (Disabled), the driver does not emulate keyset cursors. If an application requests a keyset cursor and this option is set to 0, the driver uses a static cursor and returns a message that a different value was used.
Determines whether SQLDescribeParam returns the Datatype, ParameterSize, DecimalDigits, and Nullable information for parameters in a prepared statement.
If set to 1 (Enabled), SQLDescribeParam returns the Datatype, ParameterSize, DecimalDigits, and Nullable information for parameters in a prepared statement.
If set to 0 (Disabled), SQLDescribeCol returns the Data Type, Column Size, and Decimal Digits for the column. The value SQL_NULLABLE_UNKNOWN is returned for Nullable. SQLColAttribute returns the following attribute values:
If set to 1 (Atomic) the driver fails the entire failover process if an error is generated as the result of anything other than executing and repositioning a Select statement. If an error is generated as a result of repositioning a result set to the last row position, the driver continues with the failover process, but generates a warning that the Select statement must be reissued.
If set to 2 (Atomic Including Repositioning), the driver fails the entire failover process if any error is generated as the result of restoring the state of the connection or the state of work in progress.
If set to 3 (Disable Integrity Check), the driver does not verify that the rows that were restored during the failover process match the original rows. This value applies only when Failover Mode is set to 2 (Select).
If set to 0 (Disabled), the driver tries to connect to an alternate server only when failover is caused by an unsuccessful connection attempt or a lost connection. This value provides the best performance, but your application typically experiences a short wait while the failover connection is attempted.
If set to 1 (Enabled), the driver tries to connect to the primary and an alternate server at the same time. This can be useful if your application is time-sensitive and cannot absorb the wait for the failover connection to succeed.
If set to 1 (Enabled), the driver returns refcursors from stored procedures as result sets. The driver fetches all the data from the refcursor and then closes the refcursor. If a stored procedure returns multiple refcursors, the driver generates multiple result sets, one for each refcursor returned.
If set to 0 (Disabled), the driver returns the cursor name for refcursors. The application must fetch the actual data from the refcursor using the cursor name and must close the cursor before additional processing can be done on the statement. The application must close the cursor regardless of whether it actually fetches data from the cursor.
If set to 1 (Enabled), the driver returns column values with the timestamp with time zone data type as the ODBC type SQL_TYPE_TIMESTAMP. The time zone information in the fetched value is truncated. Use this value if your application needs to process values the same way as TIMESTAMP columns.
If set to 0 (Disabled), the driver returns column values with the timestamp with time zone data type as the ODBC data type SQL_VARCHAR. Use this value if your application requires the time zone information in the fetched value.
If set to 0 (Disabled), the driver returns column values with the time data type as the ODBC data type SQL_TYPE_TIMESTAMP. The fractional seconds portion of the value is preserved. Time columns are not searchable when they are described and fetched as timestamp
server_name is the name of the server to which you want to connect.
IP_address is the IP address of the server to which you want to connect.
An Internet Assigned Numbers Authority (IANA) value. You must specify a value for this option if your application is not Unicode‑enabled or if your database character set is not Unicode. Refer to
Chapter 4 “Internationalization, Localization, and Unicode” in the
DataDirect Connect Series for ODBC Reference for details.
where IANA_code_page is one of the valid values listed in
Chapter 1 “Values for the Attribute IANAAppCodePage” in the
DataDirect Connect Series for ODBC Reference. The value must match the database character encoding and the system locale.
where SQL_command is a valid SQL command that is supported by the database.
Determines which columns are used to comprise the keyset that the driver uses to create the initial keyset on which cursor operations are based. Greenplum does not offer a true row identifier column; the driver instead uses two hidden system columns provided by the Greenplum database, ctid and gp_segment_id. Because the database might reassign these IDs following a Vacuum operation, the driver can be configured to also include other columns to help ensure that data integrity is maintained.
If set to 1 - RowID and Searchable Columns (Enabled), the driver uses a combination of every non-LOB column in the Select list and the ctid and gp_segment_id hidden columns to build the keyset. By adding other Select list fields to the keyset, the driver is able to indicate the row cannot be found if the IDs change following a Vacuum operation.
The number of seconds to keep inactive connections open in a connection pool. An inactive connection is a database session that is not associated with an ODBC connection handle, that is, a connection in the pool that is not in use by an application.
where x is a positive integer that specifies a number of seconds.
If set to x, inactive connections are closed after the specified number of seconds passes.
Determines whether the driver uses client load balancing in its attempts to connect to the database servers (primary and alternate). You can specify one or multiple alternate servers by setting the Alternate Servers option.
If set to 0 (Disabled), the driver does not use client load balancing and connects to each server based on their sequential order (primary server first, then, alternate servers in the order they are specified).
The number of seconds the driver waits for a connection to be established before returning control to the application and generating a timeout error. To override the value that is set by this connection option for an individual connection, set a different value in the SQL_ATTR_LOGIN_TIMEOUT connection attribute using the SQLSetConnectAttr() function.
where x is a positive integer that specifies a number of seconds.
If set to x, the connection request times out after the specified number of seconds unless the application overrides this setting with the SQL_ATTR_LOGIN_TIMEOUT attribute.
Specifies how often, in seconds, the driver checks the maintenance thread. A single maintenance thread is used to enforce minimum and maximum pool sizes in the connection pool. This option is not used as a runtime connection option, but does appear in the ODBC.INI section of the Registry and in the odbc.ini file.
where x is maximum size of the SQL_LONGVARCHAR data type.
The maximum number of connections allowed within a single connection pool. When the maximum number of connections is reached, no additional connections can be created in the connection pool.
where x is maximum size of the SQL_VARCHAR data type.
The minimum number of connections that are opened and placed in a connection pool, in addition to the active connection, when the pool is created. The connection pool retains this number of connections, even when some connections exceed their Load Balance Timeout value.
where x is an integer from 1 to 65535.
The password that the application uses to connect to your database. The Password option cannot be specified through the driver Setup dialog box and should not be stored in a data source. It is specified through the Logon dialog box or a connection string.
where pwd is a valid password.
where the port_name is the port number of the server listener. Check with your database administrator for the correct number.
The number of seconds for the default query timeout for all statements that are created by a connection. To override the value set by this connection option for an individual statement, set a different value in the SQL_ATTR_QUERY_TIMEOUT statement attribute on the SQLSetStmtAttr() function.
where x is a positive integer that specifies a number of seconds.
If set to x, all queries time out after the specified number of seconds unless the application overrides this value by setting the SQL_ATTR_QUERY_TIMEOUT attribute.
An error message or warning can occur if an ODBC call causes a conversion error, or if an error occurs during code page conversions to and from the database or to and from the application. The error or warning generated is
Code page conversion error encountered. In the case of parameter data conversion errors, the driver adds the following sentence:
Error in parameter x, where
x is the parameter number. The standard rules for returning specific row and column errors for bulk operations apply.
Determines how the driver handles errors that occur within a transaction. When an error occurs in a transaction, the Greenplum server does not allow any operations on the connection except for rolling back the transaction.
If set to 0 (None), the driver does not roll back the transaction when an error occurs. The application must handle the error and roll back the transaction. Any operation on the statement other than a rollback results in an error.
If set to 1 (Rollback Transaction), the driver rolls back the transaction when an error occurs. In addition to the original error message, the driver posts an error message indicating that the transaction has been rolled back.
The default user ID that is used to connect to your database. Your ODBC application may override this value or you may override it in the logon dialog box or connection string.
where userid is a valid user ID with permissions to access the database.
See “Using the XML Data Type” for further information about the XML data type.
If set to -4 (SQL_LONGVARBINARY), the driver uses the description SQL_LONGVARBINARY for columns that are defined as the XML data type.
If set to -10 (SQL_WLONGVARCHAR), the driver uses the description SQL_WLONGVARCHAR for columns that are defined as the XML data type.