Add an ability to reset custom setting to default and remove it from table's metadata.
This will allow to rollback the change without knowing the system/config's default.
Signed-off-by: Aleksei Semiglazov <asemiglazov@cloudflare.com>
add the FIRST keyword to the ADD INDEX command to be able to add index in the beginning of the list.
Signed-off-by: Aleksei Semiglazov <asemiglazov@cloudflare.com>
TODO (suggested by Nikolai)
1. Build query plan fro current query (inside storage::read) up to WithMergableState
2. Check, that plan is simple enough: Aggregating - Expression - Filter - ReadFromStorage (or simplier)
3. Check, that filter is the same as filter in projection, and also expression calculates the same aggregation keys as in projection
4. Return WithMergableState if projection applies
3 will be easier to do with ActionsDAG, cause it sees all functions, and dependencies are direct (but it is possible with ExpressionActions also)
Also need to figure out how prewhere works for projections, and
row_filter_policies.
wip
