There is Serverless SQL Pool which queries data from files Azure Storage Account.
The SQL pool is located in Central US, and Azure Storage account is located in Central India.
Files are currently in Parquet format, with some files having size up to 25 GB.
Which of the options tells about possible ways to increase the performance? (Multiple Choice)
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A. B. C. D.Correct Answer: A, C.
Colocating Azure Storage account and serverless SQL pool is definitely increasing the network latency, which in fact plays a significant role in the performance of queries.
Once they are in the same region, they will have the least network latency-related performance degradation.
When you have a larger target file, the query performance will get degraded.
But if you split them into smaller files, the parallel query performance can actually improve the overall total performance.
There may be more than one service or application accessing the storage account which you use here.If these multiple services can add up, the IOPS requirements may reach more than the maximum network performance level of the storage account, and thus automatic throttling kicks in.
Option A is correct: Bringing SQL Pool and Azure Storage accounts to the same region can help in decreasing the latency, thus increasing the overall performance of the query.
Option B is incorrect: Parquet files have better query efficiency than CSV files.
So, converting to CSV will only decrease the performance.
Option C is correct: When you have a large target file, splitting them into multiple smaller files will increase the query performance.
Option D is incorrect: There may be more than one service or application accessing the storage account which you use here.
The IOPS requirements if these multiple services can add up and may reach more than the limit, azure automatically implements storage throttling.
But this will make the SQL pool to run queries at a slower pace until throttling is resolved.
So, this will not increase the query performance.
To have better query performance, it's better to dedicate the storage account for SQL pool only and limit other applications accessing this storage account.
The performance of the Serverless SQL Pool can be improved by adopting the following options:
A. Bring SQL pool and Azure Storage account to the same region - This is an effective approach that can enhance the performance of the SQL pool. Since the SQL pool and the Azure Storage account are located in different regions, data transfer may take longer due to increased latency. If the SQL pool and Azure Storage account are located in the same region, the latency would be reduced, resulting in faster data transfer and improved performance.
B. Convert Parquet to CSV - This option may not have a significant impact on performance since the Parquet format is optimized for query performance and storage efficiency. However, if the queries in the SQL pool do not use complex structures, converting to CSV may result in a reduction in storage overhead and increase in query performance.
C. Split a large file into multiple smaller ones - If some of the files are very large, splitting them into smaller ones may be an effective approach. This can help reduce the amount of data that needs to be scanned by the SQL pool, which can result in faster query performance.
D. Enable Azure Storage throttling - Enabling Azure Storage throttling may not be the most effective option since it may restrict data transfer and, consequently, limit the performance of the SQL pool.
In summary, the most effective options for improving the performance of the Serverless SQL Pool are A (bringing the SQL pool and Azure Storage account to the same region) and C (splitting a large file into smaller ones).