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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With 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.

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BLOBs (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.

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Currently you can update your database through:

1. Flex2SQL
2. dbBuilder
3. DataFlex restructure commands
4. Directly on the SQL Server and manually changing INT files

It is common to have a DBA that wants to review all schema changes to the database, which makes options 1-3 difficult, or outright prohibited by the DBA. Option 4 is manual and prone to errors.

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The Mertech Drivers allow to improve performance when inserting records by using the SQL_SAVE_BUFFER macro command. You can specify a block of records, that will be submitted in batch to the server, instead of having each record be saved at a time.

You can set the block size based on the DF_FILE_RECORDS_USED attribute from the source table or knowing the number of records that will be inserted and, for example, multiplying the number by 0.10 to get save batches of 10% of the table size.

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