Creating collections
CQL defines the following collection data types:
Collections are intended for insertion and retrieval as a collection. Thus, Apache Cassandra reads collections in their entirety, and can affect retrieval performance. A good rule of thumb is that sets are more performant than lists, so use a set if you can. Collections should be smaller than the following maximum size to prevent querying delays.
Guard rails for non-frozen collections:
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No more than 2 billion items in a collection.
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Maximum size of an item in a
setis 65,535 bytes. -
Maximum size of an item in a
listormapis 2 GB. -
Maximum number of keys in a
mapis 65,535. -
Lists can incur a read-before-write operation for some insertions.
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Collections are not paged internally. |
Collections cannot be sliced;
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The limits specified for collections are for non-frozen collections. |
