v.23.11Improvement

Issue with Slow Connection to PG Causing Query Cancellation Due to Incorrect URL

It took too much time to connnect to PG when URL is not right, so the relevant query stucks there and get cancelled. #56648 (jsc0218).
Improved connection timeout handling for PostgreSQL dictionary sources to prevent query hangs when the connection URL is incorrect.

Why it matters

Previously, attempts to connect to PostgreSQL using an incorrect URL caused long delays and query cancellation due to extended connection timeouts. This feature addresses that issue by reducing the connection wait time, ensuring that queries do not get stuck and are cancelled more promptly, improving overall system responsiveness and reliability.

How to use it

This improvement is applied internally to the PostgreSQL dictionary source connections. Users do not need to make changes in their SQL or configuration; the connection timeout for PostgreSQL dictionaries is now handled more efficiently within the ClickHouse system.