[ https://issues.apache.org/jira/browse/CASSANDRA-12923?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
C. Scott Andreas updated CASSANDRA-12923: ----------------------------------------- Component/s: CQL > Decimal type has inconsistent equality semantics when used in partition key > --------------------------------------------------------------------------- > > Key: CASSANDRA-12923 > URL: https://issues.apache.org/jira/browse/CASSANDRA-12923 > Project: Cassandra > Issue Type: Bug > Components: CQL > Reporter: Branimir Lambov > Priority: Major > > Unlike {{double}} or {{float}}, for {{decimal}} used as primary key in > Cassandra we have that {{3 != 3.0}} even though {{3 <= 3.0}} and {{3 >= 3.0}}: > {code} > cqlsh:keyspace1> create table testdec (key decimal primary key, value int); > cqlsh:keyspace1> insert into testdec (key, value) values (3.0, 3); > cqlsh:keyspace1> select * from testdec; > key | value > ------+------- > 3.0 | 3 > (1 rows) > cqlsh:keyspace1> select * from testdec where key = 3; > key | value > -----+------- > (0 rows) > cqlsh:keyspace1> select * from testdec where key = 3.0; > key | value > -----+------- > 3.0 | 3 > (1 rows) > cqlsh:keyspace1> select * from testdec where key >= 3 and key <= 3 ALLOW > FILTERING; > key | value > -----+------- > 3.0 | 3 > (1 rows) > {code} > The reason for this is that we use the key's bytes (as produced by > {{BigDecimal}}) to form the token: > {code} > cqlsh:keyspace1> select * from testdec where token(key) = token(3); > key | value > -----+------- > (0 rows) > cqlsh:keyspace1> select * from testdec where token(key) = token(3.0); > key | value > -----+------- > 3.0 | 3 > (1 rows) > {code} > as well as to check key matches in > [{{BigTableReader.getPosition}}|https://github.com/apache/cassandra/blob/trunk/src/java/org/apache/cassandra/io/sstable/format/big/BigTableReader.java#L217]. > The solution is to always store a canonical form of each key. In this case, > such a value that the decimal's _unscaled value_ is not divisible by 10. > This problem may be affecting other types as well. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org For additional commands, e-mail: commits-h...@cassandra.apache.org