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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
by didip 5y ago
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.
- hodgesrm 5y agoClickHouse 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.