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IITDBGroup / gprom

GProM is a middleware that adds support for provenance to database backends.
http://www.cs.iit.edu/%7edbgroup/research/gprom.php
Apache License 2.0
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Postgres SQL serializer uses EXCEPT instead of EXCEPT all for bag difference #63

Closed lordpretzel closed 3 years ago

lordpretzel commented 3 years ago

GProM relational algebra is bags, so difference should be

SELECT * FROM r EXCEPT ALL SELECT * FROM s

but is

SELECT * FROM r EXCEPT SELECT * FROM s