Updating Large Tables In SQL Server And Oracle

Kevin Feasel

2017-04-12

Data

Jana Sattainathan has a post on how he was able to move and update billions of rows, using both Oracle and SQL Server as examples:

The key thing to remember with SQL Server is to convert to a non-integer value by using a “decimal” as shown in the above example with “10.”. This is the same as saying “10.0”. Without the “.”, it will result in uneven splits from rounding errors of integers. It is not the result that you intend to have it you want accurate results.

To show you the difference, I have included the SQL and results of a query that uses “.” and the other that does not, with “.” being the only difference:

It’s a good article, and definitely an important thing to think about when you have large tables.

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