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Re:ClickHouse, Inc. by didip on Monday September 20, 2021 @02:09PM (#28596827)
ClickHouse competes with OLAP storages like Druid or Pinot.

I don't know about ClickHouse but the other 2 uses bitmap indexes to make storing petabytes of data affordable.

Row oriented databases would struggle to compete against ClickHouse. They are easily an order of magnitude slower.

Re:ClickHouse, Inc. by hodgesrm on Monday September 20, 2021 @06:53PM (#28600074)
ClickHouse uses skip indexes. They basically answer the question "is the value I'm seeking not in the block."

For example, there are a couple varieties of Bloom filters, which allow you to test for presence of string sequences in blocks. This allows ClickHouse to skip reading and uncompressing blocks (actually called granules) unnecessarily.