Query Performance in bundled requests

Update: Better title and format corrections

Hi %,

in order to be able to readjust the effects of the stored procedure and, if necessary, to save turnaround times, different requests can be concatenated using semicolons for bundling several statements in one request. We did some tests against a postgres cluster.

The results in terms of optimizations are as follows:

Batchsize | clients| count Queries | average s/query| comment
--------------|---------|----------------------|----------------------|-
1 | 1 | 15.86k | 2.24ms |
10 | 1 | 31.80k | 332us |
25 | 1 | 31.75k | 312us |
50 | 1 | 32.00k | 280us |
100 | 1 | 32.00k | 286us |
| | | |
1 | 2 | 57.1k | 733us | Drop to 30k after some time!!
10 | 2 | 63.6k | 323us |
25 | 2 | 63.5k | 308us |
50 | 2 | 64k | 293us |
100 | 2 | 67.2k | 290us |
| | | |
1 | 10 | 158.6k | 2.15ms |
10 | 10 | 298.9k | 383us | Drop to ~200k!!
25 | 10 | 225k | 1.16ms |
50 | 10 | 192k | 1.55ms |
100 | 10 | 201.6k | 1.44ms |
| | | |
10 | 50 | 800k | 2.2ms |

It seems to be saturated here at around 200k requests per minute, the question remains why this is so.

Does anyone has experience with something similar or are there some hints about how to optimize the postgres cluster for such bundled statements?

Thanks and best regards

Dirk