tarantool / tarantool/tarantool
sql: magic constants in query planner
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@tsafin is already working on this.
Since Feb 20, 2020.
performance
sql
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Description
Currently, query optimizer contains a lot of magic constants which have remained from the original SQLite code. They should be investigated and benchmarked.
For instance: skip-scan optimization comes into play when the number of duplicates is about 18 or more in the left-most column of the index, i.e. query planner would rather do index search than full-table scan. For Tarantool this number may not be the most optimal.
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