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These are orthogonal. An index is used to prevent a full scan of the key space in order to find a record. You have indexes in both row and column oriented datab
by beoberha 6y ago
These are orthogonal. An index is used to prevent a full scan of the key space in order to find a record. You have indexes in both row and column oriented databases.
What a column-store database gets you is fewer I/Os on reads since all the data for a column is stored together. This is ideal for some analytic queries on warehouse databases with wide rows.
- jdmichal 6y agoA database can and will also scan an index and not even touch the table if the index has all the data it requires. I haven't tried it, but the idea of creating an index with just the data necessary for aggregation isn't far fetched. https://www.postgresql.org/docs/12/indexes-index-only-scans.html https://www.postgresql.org/docs/12/indexes-index-only-scans....
- brudgers 6y agoIn a sense storing column values in an index is how row based databases convert to column based. Do that for all the columns and you are logically close. Execution is another matter.
- deleted 6y ago[deleted]