DataFlex only supports five physical data types: NUMERIC, ASCII, DATE, TEXT and BINARY. The sixth, OVERLAP, is a logical type which maps to any one of the physical types. In the SQL world however, there are many different data types that the driver has to support. This is especially important when you are connecting to applications using the same SQL server as your DataFlex application but developed in other languages.
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Working with new SQL Server 2008 data types
October 26th, 2011New Feature: Lazy Open Mode
September 20th, 2011Mertech’s new Lazy Open mode feature is designed to improve an application’s initialization performance by deferring table setup. Lazy Open mode delays the setup of table metadata (table, columns, indexes description) in memory until a field is accessed, even if an OPEN command is issued.
Custom OEM to ANSI Translation
August 29th, 2011Mertech’s drivers have a standard OEM to translation based on the Windows API. When this feature is enabled, data sent to the SQL database is translated from the OEM to ANSI Character set and from ANSI to OEM before the data is sent back to the application.
The new version 11 drivers have a new feature available that allows the user to customize the mapping value for the OEM to ANSI translation. Basically the user can customize the OEM and the ANSI Character Translation using a macro command or through the mertech.ini file entry. The difference between these two approaches it is that the macro command must be added to each application, which means that some code has to be added and then the application source code has to be recompiled. But on the other hand, the use of the mertech.ini introduces the use of the Custom OEM to ANSI Character Translation automatically when the INI file is read during the driver initialization.
Case handling
June 28th, 2011With previous driver versions, Mertech allowed object names to be either all upper case or all lower case. The field names followed the convention selected for the table name. Now users are able to determine how the driver handles table and field names.
Blob Handling in DataFlex with Mertech’s Drivers
May 10th, 2011BLOBs (binary large object) are very large, variable length, binary or character data objects. BLOBS are typically documents (e.g., .pdf, .doc) or pictures (e.g., .jpeg, .gif, .bmp).
NOTE: Related terms, LOB (large object) and CLOB (character large object in Oracle), are used to refer to large objects consisting entirely of text data.