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SNITrace, formally BIDTrace, is an deeper level of tracing for the Microsoft SQL Server TDS consumers and providers.
Terms and Brief History
Before I dive into the details here is a brief history and related terminology.
BID
Built-In Diagnostics (BID) is the former name replaced with SNI. The original tracing was added as BIDTrace and since then many of the functions and macros were renamed to SNITrace* as improvements were made and features added.
SNI
Server Network Interface (SNI) is centralized code, shared among the SQL