2018: Production Operations Team
When data is inserted into ClickHouse, it creates one or more blocks (parts). In replicated environments, such as ClickHouse Cloud, a hash is also written in ClickHouse Keeper. Subsequent inserted blocks are compared against these hashes and ignored if a match is present. This is useful since it allows clients to safely retry inserts in the event of no acknowledgement from ClickHouse e.g., because of a network interruption. This requires blocks to be identical i.e., the same size with the same rows in the same order. These hashes are stored for only the most recent 100 blocks, although this can be modified. Note higher values will slow down inserts due to the need for more comparisons.。关于这个话题，新收录的资料提供了深入分析
。新收录的资料是该领域的重要参考
making the performance cost visible in the source.
Blue: Words before "Castle"，更多细节参见新收录的资料
Credit: Alex Bracetti / Mashable