Vlad Drumea explains what it means implicitly to convert:
If you’re here, you most likely know what a data type conversion is, but, in short, it’s the operation of converting a value from one data type to another.
There are two types of conversions in SQL Server:
- explicit – which are done by explicitly applying the CAST and CONVERT functions on a column, variable, or value.
- implicit – when CAST and CONVERT are not used explicitly, but SQL Server ends up doing the conversation behind the scenes due to two distinct data types being compared.
Read on to learn more about which types of implicit conversion are relevant for performance and what you can do instead.