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How does Cassandra store null values internally? Does it take up any storage space at all? I'm writing an application that uses a table with many many columns (100s) to represent varying types of data, so the columns have names like "text1", "text2", "number1", "number2", etc. and then there is an external JSON schema that maps what column represents what value for a specific data type. So, it could be for a certain data type that many columns have null values, and I have not been able to find anything concrete regarding the storage space (if any) that would be taken up by the null values.
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Cassandra does not allow null clustering key values.
update keyspace. table set ric=null where code='code'; You can also use null in insert statements, but if you omit the value it's the same as saying null so there's no point.
In Cassandra, deleted data is not immediately purged from the disk. Instead, Cassandra writes a special value, known as a tombstone, to indicate that data has been deleted. Tombstones prevent deleted data from being returned during reads, and will eventually allow the data to be dropped via compaction.
Cassandra allows 2 billion columns per row.
As long as you don't actually specify the name of the column and value null, it won't consume any space. E.g.
row1 col1 col4
val1 val4
row2 col1 col2 col4
val1 val2 val4
row3 col3 col4
val3 val4
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