Кадр: Reuters TV
Deduplicating at query time can be achieved by grouping the data on the fields, which uniquely identify a row, and using the argMax function with a date field to identify the last value for other fields. ReplacingMergeTree allows rows with the same sorting key (ORDER BY key) to be deduplicated on merges. Note this is "best effort" only: sometimes parts will not be merged with the merge process scheduled at non-deterministic intervals. It, therefore, does not guarantee the absence of duplicates. Users can also utilize the FINAL modifier to force this deduplication at SELECT time. While FINAL does add overhead, it has received significant performance improvements in recent versions including multi-threaded processing, and is suitable for many production workloads.
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Kuwait’s oil cutback started with about 100,000 barrels a day as of early Saturday and is expected to almost triple on Sunday, with further gradual reductions depending on storage levels and the status of Hormuz, a person with direct knowledge of the plan said, asking not to be named because the details are private.
To fix this, I moved to Unicode Block Elements. Block elements are a (weirdly incomplete) set of blocky unicode characters like UPPER_HALF_BLOCK (▀), LOWER_HALF_BLOCK (▄), and FULL_BLOCK (█) 1.