Summary

After upgrading to 25.2.2 some users may see a performance degradation on certain queries

Reported issue

The problem can manifest on different queries against Iceberg tables. The TABLE_FUNCTION operator in particular can show a large increase in startup time - sample shows V24.x on left, v25.2.2 on right

Relevant versions

Dremio 25.1.0 to 25.2.2

Cause

There was a known defect reported in internal jira DX-100856 which addresses some inefficiencies in reading column data from Iceberg tables.

Steps to resolve

Upgrade to Dremio 25.2.4