Convert(int,sys.fn_sqlvarbasetostr(hashbytes('md5','1455985476'))) -

: Selecting a deterministic but seemingly random subset of rows (e.g., WHERE ABS(HashConvert) % 10 = 0 for a 10% sample).

: Distributing data rows into different "buckets" or shards by hashing a unique ID. : Selecting a deterministic but seemingly random subset

For the specific input '1455985476' , the MD5 hash is 792106533f84b730c64951a1ea702c78 . Converting the relevant portion of this hex value to a signed 32-bit integer results in: Common Use Cases Converting the relevant portion of this hex value

: Creating a non-obvious integer ID from a sensitive string. The Result The SQL expression you provided is

: This attempts to cast that hex string into a 4-byte integer. Because the hash is much larger than an integer, SQL Server typically truncates the value, often resulting in an arithmetic overflow or returning a signed integer based on the last 4 bytes of the hash. The Result

The SQL expression you provided is a specific method used in SQL Server to generate a or "sharding key" from a string value (in this case, the string '1455985476' ). Breaking Down the Code