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Which is the best way to update a huge table?
Updating a table with so much data is obviously going to take time. The best what you can do is – Update the Table in batches. OR AS it is a staging table, you might be selecting the data from this table to insert/update into your actual tables. Then just use a CASE..END statement in your SELECT part as under – Hope, this helps !
How to update large table in SQL Server?
Many a times, you come across a requirement to update a large table in SQL Server that has millions of rows (say more than 5 millions) in it. In this article I will demonstrate a fast way to update rows in a large table
How to improve the performance of SQL update?
The issue with this query is that it will take a lot of time as it affects 2 million rows and also locks the table during the update. You can improve the performance of an update operation by updating the table in smaller groups. Consider the following code:
How to update large tables in PostgreSQL 9.2?
If possible, you should drop all the indexes, triggers and foreign keys while the update runs and recreate them at the end. Adding a nullable column without a default value is a cheap operation. Writing the actual data of the column is the expensive part. Converting between some data types does not require a full table rewrite since Postgres 9.2.
How to update a very large Oracle table?
Answer: Super large table or small table, there are some techniques for minimizing total response time for a very large update. See these notes on high performance table updates. Also see my other notes on high performance delete, update and insert DML for very large tables:
How long does it take to update a table in SQL Server?
As you can see from the above, the query only took around 14 seconds to update 1,000,000 rows. If SOW_Number is more selective, the time required will be proportionally less. As you’ve identified in your question, dropping the clustered index does not help increase performance of the update query.
Is there a way to update all rows in a table?
If it is non-clustered, each iteration may require a scan. You can check the execution plan to verify. If you are updating most of the rows in the table, you might try updating rows in batches by the clustered index key. For example: @Todd: It just doesnt return anything.