Skip to main content

BIGINT - Upper limit - Overflow - SQL Server

BIGINT upper limit is 2^63-1 (9,223,372,036,854,775,807). For complete reference check out this MSDN article

Recently I was asked when we use INT data type and it reaches its limit what do we do? The following is the error message we would see when it reaches its upper limit.


Arithmetic overflow error converting IDENTITY to data type int.
Arithmetic overflow occurred.

Though there are multiple solutions, one of the option for us is to change the datatype to BIGINT.

The person who asked me wasn't satisfied with this answer. He was worried is this a permanent solution? Won't BIGINT also overflow / reach its limits sooner or later?

Obviously BIGINT would also reach its limit but it would take really LOTS of years + millions of transactions per second for it. Actually I wouldn't bother about it at all for the reasons explained below.

Let's take few examples and see how many years will it take for BIGINT to reach its upper limit in a table:

(A) Considering only positive numbers, Max limit of BIGINT = 9,223,372,036,854,775,807
(B) Number of Seconds in a year = 31,536,000

Assume there are 50,000 records inserted per second into the table. Then the number of years it would take to reach the BIGINT max limit is:

9,223,372,036,854,775,807 / 31,536,000 / 50,000 = 5,849,424 years

Similarly,
If we inserted 1 lakh records per second into the table then it would take 2,924,712 yrs
If we inserted 1 million (1000000) records per second into the table then it would take 292,471 yrs
If we inserted 10 million (10000000) records per second into the table then it would take 29,247 yrs
If we inserted 100 million records per second into the table then it would take 2,925 yrs
If we inserted 1000 million records per second into the table then it would take 292 yrs

By this we would have understood that it would take extremely lots of years to reach the max limit of BIGINT. May be end of world would be earlier than this :) Atleast I have not seen (or) heard of any application which has exceeded the BIGINT's max limit as of now. Please feel free to let me know if you have seen any.

By the way, if you are wondering how we calculated the number of seconds in a year.
It is just 365 days * 24 hours * 60 minutes * 60 seconds = 31,536,000 seconds.
Labels:

Comments

Ravi said…
Twitter anticipated such situation and implemented Snowflake. Refer to https://dev.twitter.com/docs/twitter-ids-json-and-snowflake
10:12 PM, May 28, 2012
Post a Comment

Popular posts from this blog

My Wedding Anniversary :)

Six years back on the same day I married Sai Lakshmi (12-July-2000). I know Sai for almost 13 years now :) I fell in love with her during my 12th standard. I know @ 17 yrs any person wouldn't be matured enough to make a big decision like this. But thank God my choice was perfect :) Even now, very often we used to think about the past and laugh at our behaviors/actions then. My love story would be really interesting (at least for me and Sai :)) and I am sure none of you guys would be interested in reading about it so lemme not get into it in-depth. But one thing which I want to share is "Without Sai, I wouldn't have entered into the IT field at all". She was instrumental in convincing me to study my Master's degree in Computer Application. That's the move that changed my career. Till my schooling, my dream was to either become a "big" sportsman (Cricket and Badminton were my favorites at that time.) or an Aeronautics engineer. Unfortunately, my l...
40 comments
Read more

Script table as - ALTER TO is greyed out - SQL SERVER

One of my office colleague recently asked me why we are not able to generate ALTER Table script from SSMS. If we right click on the table and choose "Script Table As"  ALTER To option would be disabled or Greyed out. Is it a bug? No it isn't a bug. ALTER To is there to be used for generating modified script of Stored Procedure, Functions, Views, Triggers etc., and NOT for Tables. For generating ALTER Table script there is an work around. Right click on the table, choose "Modify" and enter into the design mode. Make what ever changes you want to make and WITHOUT saving it right click anywhere on the top half of the window (above Column properties) and choose "Generate Change Script". Please be advised that SQL Server would drop actually create a new table with modifications, move the data from the old table into it and then drop the old table. Sounds simple but assume you have a very large table for which you want to do this! Then it woul...
2 comments
Read more

What should one look @ while buying a land in chennai?

Offlate people have started thinking about investing their money in lands. I too think that to be a wise decision only! As most of us know buying a land in chennai (for that matter any where in the world) isn't an easy affair. I was just wondering what all one needs to look at before deciding to purchase a land. I thought I would put down what ever I know about this subject here. [Guys pls free to correct me if I my understanding is wrong somewhere. That way, it would help me understand as well as others who might read this in future]. Here we go ... 1. One should not buy farm lands if they want to build a residential house sometime later there. Because to my knowledge its illegal to build residential houses on lands meant for irrigation. 2. Encumberance Certificate -- This is what is shortly refered as "EC". One needs to get an EC from local sub registrar office (i guess we need pay a small amount for this). From this we / our lawyers :) can find out whether the guy who ...
34 comments
Read more