Limits on Collections

General
#1

Does YCQL share the same limits as cassandra for collections?

Limitations listed in the cassandra documentation:

Observe the following limitations of collections:
- Never insert more than 2 billion items in a collection, as only that number can be queried.
- The maximum number of keys for a map collection is 65,535.
- The maximum size of an item in a list or a map collection is 2GB.
- The maximum size of an item in a set collection is 65,535 bytes.
#2

Hi @llKetanll

  • A single row can be up to 64MB in size.
  • You usually want to keep rows maximum in the 1MB - 2MB to have consistent latency.
  • Note that big collections are an anti pattern.
  • If the application warrants for a bigger number of values, it’s better to model the collection as another table.

The same is true for Cassandra. They support very big collections —> but they aren’t efficient —> you should not use them.

Also explained in docs: https://docs.yugabyte.com/latest/api/ycql/type_collection/#examples

Regards,
Dorian
Technical Support Engineer