QuestDB currently does not support native deduplication. You have multiple way to solve it:
1. Each row could include a unique identifier and then you would filter it out at a query time. think of UUID column: normally there would be no duplicated UUIDs. if there is a duplicated UUID then you know it’s caused by retrying and you should ignore the dup.
2. You could use Apache Kafka between your producer and QuestDB and then use QuestDB Kafka Connector to ingest data to QuestDB. This way you could rid off some duplicates.
There are just examples, there are other strategies too.