Performance of plain versus real time indexes in manticore search.

Is there any benchmark or information regarding the performance of plain versus real time indexes?
I remember in early sphinx versions, real time index perfomance was less than that of plain indexes.
I am curious about how the performance state of plain versus real time indexes is in current manticore versions.

Thank you.

I’ve found some old benchmarks of mid-December 2022:

This may be imperfect in terms of the returned results (that’s why the “plus/minus” icon is shown for a few records), but it shows the essence: RT tables are on-par with plain tables in terms of response time. This is because since the Sphinx times:

  • RT tables can parallelize queries among all the chunks
  • Plain tables use pseudo-sharding to do a similar thing

First of all, thank you for your informative response!

I am currently testing Manticore on a beefy server with 128 cores (256 threads with hyperthreading enabled), NVMe drive, and 512GB of RAM. I have split the index into 20 shards on a plain index, as I was using Sphinx until a few days ago.

Although I have only briefly looked at the changes in top, I used real traffic to test and noticed that performance on Manticore can be easily improved by increasing max_threads_per_query. However, the server load increases significantly with a small improvement in performance.

Would you think that RT indexes and plain indexes have similar CPU usage?

As for performance, it seems that simply increasing max_threads_per_query can improve response time easily, but at the cost of much higher CPU usage.

Do you think automatic performance increases using a high max_threads_per_query are as less, similar, or more efficient than physically sharding the index on the same local hardware?