Maximum QPS for Azure PostgreSQL Flexible Server

Question

Is there a dependency between the maximum queries per second that Azure PostgreSQL Flexible Server can support and the compute SKU of the flexible server?If not what are the factors affecting maximum queries per second that azure postgres flexible server can support?

Answer 1

Thanks for the response @Prasad Chaganti would like to utilise my azure postgres flexible server with Pgvector extension as vector database which should serve target throughput of 50 queries per second.I am using E8s_v3 Memory optimised Compute SKU with 1TB storage capacity and would like to know whether the configuration handles target throughput of 50 queries per second.Any resources to determine maximum queries per second will be helpful

Answer 2

Hi Sai,

Based on your configuration of an E8s_v3 Memory Optimized Compute SKU with 1TB storage, it is likely that the server can handle a throughput of 50 queries per second, but the actual performance will depend on several factors:

The E8s_v3 SKU has 8 vCores and 64 GB of memory. This should provide sufficient compute and memory to support 50 QPS, especially for read-heavy or moderately complex vector search queries.

Performance with the Pgvector extension will depend on factors such as:

1.Indexing method (HNSW vs IVFFLAT) – HNSW typically provides faster search times but requires more memory.

2.Distance calculation type – Cosine similarity or L2 distance can affect query time.

Ensure that connection pooling is configured properly (e.g using PgBouncer) to handle high concurrency and avoid connection bottlenecks.

Tuning settings like work_mem, shared_buffers, and effective_cache_size can enhance query performance.

The disk I/O limits associated with the SKU can affect query response times, particularly for write-heavy workloads. Ensure the IOPS and throughput are within acceptable ranges for your workload.

For more detailed insights, you can use pg_stat_statements to monitor query performance and adjust configurations as needed.

Refer: https://learn.microsoft.com/en-us/azure/postgresql/flexible-server/

I hope this information helps. Please do let us know if you have any further queries. If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.