For a simple exercise try this: If an application does not reference a column from a table, then the application is not affected by any changes made to that column. Next see what drivers you have installed already odbcinst -d -q On our CentOS 7 box, got returned: To do this we need to create a datasource template file and register that with odbcinst manager similar to what we did with the driver as follows:. This optimization can be applied to applications so that no text or image data is displayed while a user is scrolling up and down a cursor. For more information, see “Setup and Connecting.

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When using server cursors see “Cursors”the driver is optimized to not transmit the data for unbound text or image columns at the time the row is fetched. The keys are built from a set of columns that uniquely identify the rows.

For more information, see “pfNative Error Codes. Deletes generate an “invalid cursor position” error SQLState S if the application attempts to fetch the missing row. When operating asynchronously, the driver immediately returns control to the application, even before sending the command to the server.

Here is the equation used to figure the percentage of cursor used: Usage count increased to 1. When autocommit is on, each individual statement is committed by the server.

Inline TDS ODBC driver Alpha Release

The connection customization section begins with the names Tableau detected for the ODBC driver and the database vendor. The cursor does not reflect any changes made in the database that affect either the rows in the result set, or the values in the columns of those rows.


Data source definitions are stored in C: When using a default result set, there is only one roundtrip between the client and server; this occurs at the time the SQL statement is executed. The Connection properties describe the various options that can be used to establish a connection.

Installing a newer version of Instcat. The values from towhich are known as the extended characters, represent different characters in all three code pages. Tableau uses this information to associate a specific connection customization with a single type of ODBC data source.

This is more efficient than sending five separate batches to the server. Entry’s Links Quicksearch Calendar. The log file is a tab-delimited text file that can be opened in Microsoft Excel specify tab delimited in inljne wizard that appears. Archives December November October Recent You should consider these options when exploring ways to improve the functionality or performance of your ODBC connection. If the minimum resolution of the server clock is larger than the likely interval for some of the timer-based statistics, those statistics may be inflated.

This logic allows applications to effectively deal with situations where they may execute the same SELECT statement several times with different parameters.

Using ODBC with Microsoft SQL Server

When the cursor is opened in this mode, no locks are held on the underlying rows to maximize throughput. Save data for later offline use or enable fast reporting from the cache. The following statements are an example of pulling the statistics into the application:.


Inlins modifications into a single transaction must be done in a way that balances multiuser concurrency with single-user performance. SQL Trace can be used to dynamically trace statements coming inlien from different clients to a server.

Some data sources are so severely limited that Tableau is unable to complete the steps of creating a connection. Unfortunately when I tried to use it on windows compiling my usual mingw64 waywhile it compiled and installed, odgc crashed when I attempted to connect to my SQL Server R2 box table, so I gave up on it for the time being as a cross-platform solution.

Customize and Tune ODBC Connections

An application can request that the driver not log text and image modifications:. I haven’t experimented with that to see if I can replicate the issue.

The site inlinf not have to depend on all application programmers coding their SQL statements correctly in all the applications. If the primary server fails for some reason, then applications can switch to the fallback server. Application profile statistics Description TimerResolution The minimum resolution of the server’s clock time in milliseconds. This eliminates the overhead of later calls to the ODBC catalog functions for the same information which forces the driver to make roundtrips to the server.

If an application executes the same statement many times, then the overhead of having the engine compile the plan every time degrades performance.

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