[jira] [Created] (CASSANDRA-13409) Materialized Views: View cells is resurrected

["Duarte Nunes (JIRA)" <ji...@apache.org>]

Duarte Nunes created CASSANDRA-13409:
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             Summary: Materialized Views: View cells is resurrected
                 Key: CASSANDRA-13409
                 URL: https://issues.apache.org/jira/browse/CASSANDRA-13409
             Project: Cassandra
          Issue Type: Bug
            Reporter: Duarte Nunes


Consider the following commands, ran against trunk@0f054fee5c:

{code:xml}
echo "create keyspace ks WITH replication = {'class': 'SimpleStrategy', 'replication_factor': 1};" | bin/cqlsh
echo "create table ks.base (p int primary key, v1 int, v2 int) with gc_grace_seconds = 1;" | bin/cqlsh
echo "create materialized view ks.my_view as select * from ks.base where p is not null and v1 is not null primary key (v1, p);" | bin/cqlsh
echo "insert into ks.base (p, v1, v2) values (3, 1, 3) using timestamp 1;" | bin/cqlsh
bin/nodetool flush ks my_view base
echo "delete from ks.base using timestamp 2 where p = 3;" | bin/cqlsh
bin/nodetool flush ks my_view base
echo "insert into ks.base (p, v1) values (3, 1) using timestamp 3;" | bin/cqlsh
bin/nodetool flush ks my_view base
echo "select * from ks.my_view;" | bin/cqlsh

 v1 | p | v2
----+---+----
  1 | 3 |  3

(1 rows)

echo "select * from ks.base;" | bin/cqlsh

 p | v1 | v2
---+----+------
 3 |  1 | null

(1 rows)
{code}

As you can see, this incorrectly brings back cell v2=3. 

There is one definitive problem and a potential one:

* Merging rows must be commutative. If a shadowable tombstone is applied after a row tombstone, it will replace that tombstone; if a row marker shadows the shadowable tombstone before the row containing the original data is applied, then any dead cells in said data will be resurrected;
* Shadowable tombstones shouldn't compact away previous row tombstones or even deleted cells; if the relevant tombstones have been GCed from the base table, then a base table update won't carry them anymore (alongside a newer row marker).



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