Articles by tag: merge-tree

ClickHouse: deduplication and losses in MV

Analysis of data losses in ClickHouse due to block deduplication in materialized views. Settings insert_deduplicate=0 and deduplicate_blocks_in_dependent_materialized_views=1. Configure lossless storage — read the details.

Kafka Engine ClickHouse: atomicity without losses

Setting up Kafka Engine in ClickHouse for reliable inserts from streams. Demonstration of offset-commit, avoiding losses on failures. Guide for middle/senior dev.

MV in ClickHouse: data loss and control

Analysis of risks of materialized views in ClickHouse: schema errors, block insert, monitoring system.query_views_log. How to avoid losses in production. Practical code examples.