SQL insert very slow [closed]

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Every 5 seconds I want insert around 10k rows into the table. Table is unnormalized and has no primary keys or any indexes. I noticed that insert performance is very slow - 10k rows in 20 seconds, which is unacceptable for me.

In my understanding indexing could improve only searching performance but not insert. Is it true? Do you have any suggestions how it is possible improve performance?

Answer 1

You're right in that indexing will do nothing to improve the insert performance (if anything it might hurt it due to extra overhead).

If inserts are slow it could be due to external factors such as the IO performance of the hardware running your SQL Server instance or it could be contention at the database or table level due to other queries. You'll need to get the performance profiler running to determine the cause.

If you're performing the inserts sequentially, you may want to look into performing a bulk insert operation instead which will have better performance characteristics.

And finally, some food for thought, if you're doing 10K inserts every 5 seconds you might want to consider a NoSQL database for bulk storage since they tend to have better performance characteristics for this type of application where you have large and frequent writes.

Answer 2

Besides what Miky's suggesting, you can also improve the performance optimizing your db structure by for example reducing the length of varchar fields, using enums instead of texts and so on. It is also related to referential integrity, and first of all I think, you should normalize the database anyways. Then you can go on optimizing the queries.