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It's correct. Snowflake does not have indexes, and ClickHouse indexes are what they call "data skipping indexes". BigQuery, Redshift, Netezza, and Vertica also

• FridgeSeal 5y ago
  > ClickHouse indexes are what they call "data skipping indexes". That’s still an index though isn’t it? Might work slightly differently, but the purpose is still the same.
  • tomnipotent 5y ago
    Not in the same sense we consider them in traditional databases, used to find specific rows (needle in haystack). ClickHouse indexes are used to eliminate data pages to reduce IO for range queries, not to find specific rows by value.
    • tremon 5y ago
      Row-store indexes (indices?) are used for both. The first few levels of a b-tree index can be used for discarding/narrowing ranges, the leaf levels are for pinpointing a specific row. What I think you meant to say was that Snowflake does not offer user-manageable indexes, not that they don't use indexes at all.
• zX41ZdbW 5y ago
  ClickHouse has both variants: primary and seconday indexes. Primary key is range index - to quickly locate records. Secondary indexes are data skipping indexes - to quickly skip blocks of data.