what the bloody hell are you talking about ?

In SQL Server versions 7.0 and earlier, whenever a query uses a comparison operator between a column and a literal, the data type of the column is used regardless of the precedence rules. That is, if the column and the literal have different data types, the latter is always converted to the data type of the column (as long as the conversion is valid). This behavior may lead to undesired precision reduction, string truncation, or other conversions.

In SQL Server 2000, this is no longer true. A conversion is performed according to data type precedence, as it is in any other comparison. In the case where a literal is positioned higher in the hierarchy, the comparison is made between the constant and the converted column (as opposed to previous versions) and therefore, results may differ. Consequently, existing indexes may not be useful, different execution plans may be chosen, and performance may be impacted negatively.

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