ODBC Reference :: SAS(R) Federation Server 3.2: Administrator's Guide

About ODBC

This section provides functionality details and guidelines for the open database connectivity (ODBC) databases that are supported by the SAS Federation Server Driver for ODBC.

ODBC standards provide a common interface to a variety of databases, including dBASE, Microsoft® Access®, Oracle®, Paradox, and Microsoft SQL Server databases. Specifically, ODBC standards define APIs that enable an application to access a database if both the application and the database conform to the specification. ODBC also provides a mechanism to enable dynamic selection of a database that an application is accessing, so that users have the flexibility of selecting databases other than those that are specified by the application developer.

Understanding the Driver for ODBC

The SAS Federation Server Driver for ODBC enables SAS Federation Server to read and update legacy ODBC database tables. In addition, the driver creates tables that can be accessed by both SAS Federation Server and an ODBC database.

The SAS Federation Server Driver for ODBC supports most of the FedSQL functionality. The driver also supports an application's ability to submit native database-specific SQL statements.

The SAS Federation Server Driver for ODBC is a remote driver, which means that it connects to a server process in order to access data. The process might be running on the same machine as SAS Federation Server, or it might be running on another machine in the network.

Connection Options for ODBC

Overview

To access data that is hosted on SAS Federation Server, a client must submit a connection string, which defines how to connect to the data. The data service connection arguments for an ODBC-compliant database include connection options and advanced options.

Connection Options

Connection options are used to establish a connection to a data source. Specify one or more connection options when defining a data service using the CREATE DATA SERVICE DDL statement.

The following connection options are supported for an ODBC-compliant database:

Option	Description
CATALOG	`CATALOG=catalog-identifier;` Specifies an arbitrary identifier for an SQL catalog, which groups logically related schemas. For databases that do not support native catalogs, any identifier is valid (for example, catalog=myodbc). For the SQL Server, which is a multi-catalog database, CATALOG= is not required. The connection defaults to CATALOG=* unless you specify a logical name for the catalog and map it to the native catalog name in the SQL Server. For example, to map the logical catalog mycat to the native catalog named newusers, specify the following code: `catalog=(mycat=newusers);` Note: You are required to specify a catalog name for all databases except the SQL Server, which can omit the CATALOG= option, or else specify a catalog name map. Catalog name maps can be used with FedSQL only. They cannot be used to access native DBMS SQL.
CONOPTS	`CONOPTS=(ODBC—compliant database connection string);` Specifies, within parentheses, an ODBC-compliant database connection string, including any valid SAS Federation Server Driver for ODBC connection options that are not provided by SAS Federation Server connection options. For connections that do not use a DSN, include the ODBC-specific DRIVER= keyword, that is, if you do not include a DSN= connection option to specify an ODBC DSN. For example, specify DRIVER={SQL Server} followed by appropriate connection options that are valid in SQL Server connections. If you include a DSN= or FILEDSN= specification with the CONOPTS= option, do not use the ODBC_DSN= connection option. However, you can specify the ODBC database-specific connection options by using CONOPTS= and then you can specify an ODBC DSN that contains other connection information by using the ODBC_DSN= connection option.
DRIVER	`DRIVER=ODBC`; Calls the SAS Federation Server Driver for ODBC. This specifies that the data service to which you want to connect must be an ODBC-compliant database. Note: You must specify the driver.
ODBC_DSN	`ODBC_DSN=odbc dsn name` Specifies a valid ODBC-compliant database DSN that contains connection information for connecting to the ODBC-compliant database. You can use the CONOPTS= option in addition to ODBC_DSN= option to specify database-specific connection options not provided by SAS Federation Server. Do not specify the ODBC DSN in both CONOPTS= and ODBC_DSN=.

Advanced Options

conref="Resources/Snippets/advanced_option.dita#advanced_option/snippet

The following connection options are supported for an ODBC-compliant database:

Option

Description

CT_PRESERVE

CT_PRESERVE = STRICT | SAFE | FORCE | FORCE_COL_SIZE

Allows users to control how data types are mapped. Note that data type mapping will be disabled when CT_PRESERVE is set to STRICT. If the requested type does not exist on the target database, an error is returned. The options are:

STRICT The requested type must exist in the target database. No type promotion will occur. If the type does not exist, an error is returned.
SAFE Target data types will be upscaled only if they will not result in a loss of precision or scale. When character encodings are changed, the new column size will be recalculated to ensure all characters can be stored in the new encoding.
FORCE This is the default for all drivers. The best corresponding target data type will be chosen, even if it could potentially result in a loss of precision or scale. When character encodings are changed, the new column size will be recalculated to ensure all characters can be stored in the new encoding.
FORCE_COL_SIZE This option is the same as FORCE, except that the column size for the new encoding will be the same as the original encoding. This can be used to avoid <i>column size creep</i> that has been seen in some cases, but it means that the resulting column might be too large or too small for the target data.

ENABLE MULTIPLE ACTIVE RESULT SETS (MARS)

ENABLE_MARS=
                                    0 | 1

Enables or disables the use of multiple active result sets (MARS) on SQL Server. FedSQL cannot permit transactions on top of SQL Server because SQL Server only allows one cursor per transaction. Set this option to 1 (true) which gives FedSQL the ability to allow transactions under a given SQL Server connection.

DEFAULT_ATTR

DEFAULT_ATTR=(attr=value;...)

DEFAULT_ATTR is used to specify connection handle or statement handle attributes supported for initial connect-time configuration. Where attr=value corresponds to any of the options below:

CURSORS=n- Connection handle option. This option controls the driver’s use of client side result set cursors. The possible values are 0, 1 or 2.

0	Causes the driver to use client side static cursor emulation if a scrollable cursor is requested but the database server cannot provide one.
1	Causes the driver to always use client side static cursor emulation if a scrollable cursor is requested. The database server’s native cursor will never be used.
2	(Default) Causes the driver to never use client side static cursor emulation if a scrollable cursor is requested. The database server’s native cursor will be used if available – otherwise the cursor will be forward only.

Example: DEFAULT_ATTR=(CURSORS=2)

USE_EVP=n— Statement handle option. This option optimizes the driver for large result sets. The possible values are 0 (OFF) or 1 (ON), which is the default. Example: DEFAULT_ATTR=(USE_EVP=0)
XCODE_WARN=n - Statement handle option. Used to warn on character transcoding errors that occur during row input or output operations. Possible values are 0 (returns an error), 1 (returns a warning), or 2 (ignore transaction errors). Example: DEFAULT_ATTR=(XCODE_WARN=1)

DEFAULT CURSOR TYPE

DEFAULT_CURSOR_TYPE=FORWARD_ONLY
                                    | KEYSET_DRIVEN | DYNAMIC | STATIC;

Specifies a valid default cursor type for new statements. The valid options are:

FORWARD_ONLYSpecifies a non-scrollable cursor that moves only forward through the result set. Forward-only cursors are dynamic in that all changes are detected as the current row is processed. If an application does not require scrolling, the forward-only cursor retrieves data quickly, with the least amount of overhead processing.
KEYSET_DRIVENSpecifies a scrollable cursor that detects changes that are made to the values of rows in the result set but that does not always detect changes to deletion of rows and changes to the order of rows in the result set. A keyset-driven cursor is based on row keys, which are used to determine the order and set of rows that are included in the result set. As the cursor scrolls the result set, it uses the keys to retrieve the most recent values in the table.
It is sometimes helpful to have a cursor that can detect changes in the rows of a result set. A keyset-driven cursor uses a row identifier rather than caching the entire row into memory. It therefore uses much less disk space than other row caching mechanisms. Deleted rows can be detected when a SELECT statement that references the bookmark, row ID, or key column values fails to return a row.
DYNAMICSpecifies a scrollable cursor that detects changes that are made to the rows in the result set. All INSERT, UPDATE, and DELETE statements that are made by all users are visible through the cursor. The dynamic cursor is good for an application that must detect all concurrent updates that are made by other users.
STATICSpecifies a scrollable cursor that displays the result set as it existed when the cursor was first opened. The static cursor provides forward and backward scrolling. If the application does not need to detect changes but requires scrolling, the static cursor is a good choice.

Default: There is no default value.

Note: The application can still override this value, but if the application does not explicitly set a cursor type, this value will be in effect

DRIVER TRACE

DRIVER_TRACE='API | SQL | ALL';

Requests tracing information, which logs transaction records to an external file that can be used for debugging purposes. The SAS Federation Server driver writes a record of each command that is sent to the database to the trace log based on the specified tracing level, which determines the type of tracing information. The tracing levels are:

ALL Activates all trace levels.
API Specifies that API method calls be sent to the trace log. This option is most useful if you are having a problem and need to send a trace log to Technical Support for troubleshooting.
DRIVER Specifies that driver-specific information be sent to the trace log.
SQL Specifies that SQL statements that are sent to the database management system (DBMS) be sent to the trace log. Tracing information is DBMS specific, but most SAS Federation Server drivers log SQL statements such as SELECT and COMMIT.

Default: Tracing is not activated.

Note: If you activate tracing, you must also specify the location of the trace log with DRIVER_TRACEFILE=. Note that DRIVER_TRACEFILE= is resolved against the TRACEFILEPATH set in ALTER SERVER. TRACEFILEPATH is relative to the server's Content Root location.

(Optional) You can control trace log formatting with DRIVER_TRACEOPTIONS=.

Interaction: You can specify one trace level, or you can concatenate more than one by including the | (OR) symbol. For example: driver_trace='api|sql' generates tracing information for API calls and SQL statements.

DRIVER TRACE FILE

DRIVER_TRACEFILE='filename';

Used to specify the name of the text file for the trace log. Include the filename and extension in single or double quotation marks. For example: driver_tracefile='\mytrace.log'

Default: The default TRACEFILE location applies to a relative filename, and it will be placed relative to TRACEFILEPATH.

Requirement: DRIVER_TRACEFILE is required when activating tracing using DRIVER_TRACE.

Interaction: (Optional) You can control trace log formatting with DRIVER_TRACEOPTIONS=.

DRIVER TRACE OPTIONS

DRIVER_TRACEOPTIONS=APPEND | THREADSTAMP | TIMESTAMP;

Specifies options in order to control formatting and other properties for the trace log:

APPEND Adds trace information to the end of an existing trace log. The contents of the file are not overwritten.
THREADSTAMP Prepends each line of the trace log with a thread identification.
TIMESTAMP Prepends each line of the trace log with a time stamp.

Default: The trace log is overwritten with no thread identification or time stamp.

PASSWORD

PASSWORD=password;

Specifies the password that corresponds to the user ID in the database.

Note: The alias is PWD=.

USER

USER=user-ID;

Specifies the user ID for logging on to the ODBC-compliant database, such as Microsoft SQL Server, with a user ID that differs from the default ID.

Note: The alias is UID=.

The following examples are of valid connection strings.

This connection string specifies an ODBC DSN:

driver=odbc; uid=scott; pw=roger; odbc_dsn=myOracleDSN;
    catalog=odbc_oracle;

This connection string specifies catalog name maps to access multiple catalogs on Microsoft SQL Server:

driver=odbc; uid=jfox; pw=mypw; odbc_dsn=mySQLdsn;
    catalog=(cat1=mycat; cat2=testcat; cat3=users;

Wire Protocol Driver Usage Notes

SAS Federation Server provides a number of wire protocol ODBC drivers that communicate directly with a database server, without having to communicate through a client library. When you configure the ODBC drivers on Windows or UNIX, you have the opportunity to set certain options. SAS products run best when these options are selected. Some, but not all, are selected by default.

Windows	The options are located on the Advanced or Performance tabs in the ODBC Administrator.
UNIX	The options are available when configuring data sources using the `dfdbconf` tool. Values can also be set by editing the odbc.ini file in which their data sources are defined.

Note: For DSNs where a wire protocol driver is specified and the catalog option is selected, only the schemas that have tables or views will be listed (not all schemas that exist). If you require different behavior, create a DSN without the catalog option.

When configuring an ODBC DSN using the 32-bit MySQL Wire Protocol driver, select the following options on the Advanced tab:

Application Using Threads
Enable SQLDescribeParam

Configure the following Advanced options for the SQL Server Legacy Wire Protocol driver:

Enable Quoted Identifiers
Fetch TWFS as Time
Fetch TSWTZ as Timestamp

Note:

Significant performance improvements have been realized when using the SQL Server Legacy Wire Protocol Driver, as compared to the SQL Server Wire Protocol Driver.
The SQL Server Legacy Wire Protocol Driver does not support transactions when used with FedSQL enabled because the driver only allows a single statement per connection while FedSQL requires multiple statements per connection when using transactions.