michalursa opened a new pull request #11150: URL: https://github.com/apache/arrow/pull/11150
Hash join node implementation. Complete implementation of in-memory hash join, except for: - residual predicates (non-equality join conditions accompanying equality conditions in case of outer joins) - support for dictionary data types. This code is NOT TESTED at all yet. Testing in progress. Code will be updated with tests. This is a simple implementation that is not performance optimized. More advanced implementation (adding e.g. Bloom-like filters) will follow. Supports all 8 flavors of the join: left semi, left anti-semi, right semi, right anti-semi, inner, left outer, right outer and full outer join. Note that left semi join, for instance, is not the same as right semi join with inputs swapped. They have the same effect but the algorithm is different in both cases. Left semi join will filter out rows with no matches coming from left (first) child exec node. Right semi join will keep track of whether there was a match for each row for right (second) child exec node inserted into a hash table and output hash table rows with matches at the end. Supports the same keys as hash group by node, except for lack of support for dictionaries and strings with 64-bit offset. Supports choosing for each corresponding pair of key fields whether null should match null or not. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
