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AdeptSQL Diff Online Help

The configuration options for DataDiff can be found as the last two pages in the Schema Options dialog. Even though the pages are pretty much self-explaining, they are shown and commented below.

[Diff 1.90 or later]: Please note that in the recent version BLOB thresholds can be set separately for each column of the compared tables.  The threshold described below now works just as a suggested default value in the column configuration dialog.

Although DataDiff can handle (load, display and compare) pretty large amounts of data, it is necessary to remember that all the data from the two table is actually loaded into memory. Depending on the amount of RAM installed on your machine and other software running simultaneously, this may be an additional heavy load on the system resources which could slow down your system significantly.

And the fastest way to consume all your system resources is to compare tables with large BLOB data in them. To avoid such situations, DataDiff would compute a 16-byte MD5 "digest" for any BLOB value longer than the threshold value specified in this dialog box. The MD5 digest are almost guaranteed to be different if the original data was different, so they can be compared instead of the original data. Of course, it is impossible to recover the original data from the digest, so the digested columns can not be displayed or scripted (unless you use server-side scripting). By default, the cut-off size for BLOBs is 4Kb, but you can change it to anything up to 64Kb. The data storage format in DataDiff buffers does not allow to keep values longer than 64K. And scripting such a monstrous piece of data as a 0xXXXXX... string would not be a good idea anyway.

This page controls the formatting of INSERT statements generated by DataDiff.

Batch rows. Specifies whether to send each statement to the server separately or in a batch of N rows. Specify 0 to put all SQL in one batch (no delimiters between statements), 1 to put a delimiter after each one, or a larger number to group every N statements.

Always specify columns. If checked, INSERT INTO will always contain the list of columns for which the data is inserted. Otherwise, the list will be omitted if the statement inserts all columns (which makes for much shorter SQL code, but may cause unexpected errors if the table structure changes).

Datetime format. The program can generate datetime literals in any of the predefined formats supported by MS SQL Server (see MS Transact-SQL documentation for the description of format parameter of the CONVERT() function). Additionally, you can tell the program to include the explicit CONVERT as well, thus ensuring that the string representing the date will be correctly converted into datetime value regarding of default datetime format set on the server.