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Re: Low performance between datacenters - Mailing list pgsql-performance

From Vitalii Tymchyshyn
Subject Re: Low performance between datacenters
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Msg-id CABWW-d1YWwEYniKnGcXJp84Qz3KkifHSJNscVxrRwZMCZjrqNA@mail.gmail.com
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In response to Low performance between datacenters  (Tamás PAPP <tomposmiko@gmail.com>)
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Often it happens because of the low batch size for fetching data. This makes client wait unnecessarily while reading rows. I am not sure which client are you using, but in java this can be controlled on per-statement level, see 

I believe there is also a connection parameter to set the default value, but I don’t remember out of top of my head. You can definitely set it on connection, see 

нд, 7 лип. 2024 р. о 10:17 Tamás PAPP <tomposmiko@gmail.com> пише:
hi All,

I am new on the list.
I hope someone can give me an adequate answer or good advice about my problem.

I have a client (normally a web service, for testing the psql client) in GCP. There is a PSQL server in another DC. The ping response time is 20ms.
I measured the bandwidth via scp and it is more than 1Gb/s which is more than enough IMO.


The psql connection between the DCs for me was unexpectedly slow.
I would expect a bit slower query without data ('select now()') due to the increased latency and somewhat similar speed of data transfer.
What I see is that

select now() increased from 0.7ms to 20ms which is OK.
And 'select *' on a table with 3082 rows (so it's a small table) increased from 10ms to 800ms.


Is this normal? Can I improve it somehow?


Thank you,

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