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| SQL Syntax clause | Relational Operator | Logical plan node (opt) | Logical plan node (planNode) | Execution processor | Notes |
|---|---|---|---|---|---|
| FROM <tablename> | atom | Scan | scan, revscan | TableReader | |
| IndexJoin | index-join | IndexJoiner | Necessary when an index being selected from doesn't contain all of the columns that the SELECT needs. Jumps back to the primary index to retrieve the other necessary data. | ||
| VirtualScan | virtual table | ??? | |||
| ROWS FROM(...) FROM srf_builtin() | N/A | project set | project set | ??? | |
| WHERE | selection (σ) | Select | filter | (Embedded in every processor) | |
| SELECT | projection (Π), rename (ρ) | Project | render | (Embedded in every processor) | |
JOIN FROM a,b WHERE EXISTS | natural join (⋈) anti join (▷) semi join (⋉) | InnerJoin, InnerJoinApply LeftJoin, LeftJoinApply RightJoin, RightJoinApply FullJoin, FullJoinApply SemiJoin, SemiJoinApply AntiJoin, AntiJoinApply | join (or others depending on join elimination and other xforms) | (Translated to either of the joins below depending on circumstances) | The "apply" variants are used as intermediate representation when there is a correlated subquery. |
| HashJoiner | Less efficient than merge join - has to buffer an entire side in memory. | ||||
| MergeJoin | join w/ specific algorithm | MergeJoiner | Efficient - can "stream rows" from each side. | ||
| LookupJoin | join w/ specific algorithm | JoinReader | |||
| ZigzagJoin | join w/ specific algorithm | ZigZagJoiner | |||
| ORDER BY | (Embedded in logical plan nodes as required output ordering) | sort | (Translated to either of the sorters below depending on circumstances) | ||
| sortAllProcessor | |||||
| sortTopKProcessor | |||||
| sortChunksProcessor | |||||
| GROUP BY | aggregation | GroupBy, ScalarGroupBy | groupby | (Translated to either of the groupers below depending on circumstances) | |
| orderedAggregator | |||||
| hashAggregator | |||||
| UNION | set union (∪) | Union | ??? | ||
| EXCEPT | set difference (\) | Except | ??? | ||
| INTERSECT | set intersection (∩) | Intersect | ??? | ||
| subquery aka (SELECT... ) | N/A | subquery | N/A | ||
| DISTINCT | Distinct | distinct | Distinct | ||
| DISTINCT ON | DistinctOn | distinct (with "distinct-on" attribute) | Distinct | ||
| OrderedDistinct | |||||
| LIMIT | Limit | limit w/ limit field | ??? | ||
| OFFSET | Offset | limit w/ offset field | ??? | ||
| OVER / PARTITION BY | Not implemented yet | window | windower | ||
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