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DataFabricRus / scylla-rdf

An RDF store based on ScyllaDB and Eclipse RDF4J
MIT License
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Counting cardinality estimations may become negative #3

Open KMax opened 5 years ago

KMax commented 5 years ago

The card(c), card(p) and card(p, o) may be below zero, which is wrong. Maybe fixed by using the conditional UPDATE which would check if the counter is not less than the decrement.

KMax commented 5 years ago

INSERT ... IF NOT EXISTS employs the lightweight transactions mechanism which isn't supported by ScyllaDB yet (see https://github.com/scylladb/scylla/issues/1359). And lightweight transactions introduce a significant overhead which may be undesirable.