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Choosing appropriate DataType in SQL Server table


I have a large transaction table in SQL server which is used to store about 400-500 records each day. What is the data type should I use in my PK column? The PK column stores numeric values, for which integer seems suitable but I'm afraid it will exceed the maximum value for integer since I have so many records everyday.

I am currently using integer data type for my PK column.


Solution

  • With a type INT, starting at 1, you get over 2 billion possible rows - that should be more than sufficient for the vast majority of cases. With BIGINT, you get roughly 922 quadrillion (922 with 15 zeros - 922'000 billions) - enough for you??

    If you use an INT IDENTITY starting at 1, and you insert a row every second, you need 66.5 years before you hit the 2 billion limit .... so with 400-500 rows per day - it will take centuries before you run out of possible values... take 1'000 rows per day - you should be fine for 5883 years - good enougH?

    If you use a BIGINT IDENTITY starting at 1, and you insert one thousand rows every second, you need a mind-boggling 292 million years before you hit the 922 quadrillion limit ....

    Read more about it (with all the options there are) in the MSDN Books Online.