Why Athena v3 slower than Athena v2?

Hello,

I am currently testing Apache Iceberg as the storage type. I've created a table using Athena v3 and I updated it using MERGE INTO syntax. The first update added two rows in the table, and on the second update, I used exactly the same rows. So, the table still has 2 rows because there were no updates.

The funny thing is, when I use Athena v3 for retrieving the data, the query runs around 7-8 seconds. But when I am running the same query on Athena v2, it runs for around 4-5 secs.

Shouldn't Athena v3 be performing faster than Athena v2? What could be wrong? Am I missing something?

Thanks.