On Mon, Feb 8, 2016 at 2:10 PM, Agrawal, Pratik <paagrawa@amazon.com> wrote:
Recently we added one of the table fields from as Map<text, text> in Cassandra 2.1.11. Currently we read every field from Map and overwrite map values. Map is of size 3. We saw that writes are 30-40% slower while reads are 70-80% slower. Please find below some metrics that can help. 

My question is, Are there any known issues in Cassandra map performance?  As I understand it each of the CQL3 Map entry, maps to a column in cassandra, with that assumption we are just creating 3 columns right? Any insight on this issue would be helpful.

I have previously heard reports along similar lines, but in the other direction.

eg - "I moved from a collection to a TEXT column with JSON in it, and my reads and writes both became much faster!"

I'm not sure if the issue has been raised as an Apache Cassandra Jira, iow if it is a known and expected limitation as opposed to just a performance issue.

If I were you, I would consider filing a repro case as a Jira ticket, and responding to this thread with its URL. :D