Projection refresh failed because the query epoch was older than the Ancient History Mark (AHM), making historical data inaccessible.
Environment
Vertica 24.x
Situation
There is an issue while refreshing a newly created projection. The percent_complete in the projection_refresh table initially increases, but the operation eventually fails with the following error:
"Can't run historical queries at epochs prior to the Ancient History Mark."
According to the vertica.log, the query was trying to run at epoch 381028476, while the Ancient History Mark (AHM) had already advanced to 381030552, making the query epoch too old to be valid.
This typically indicates that the refresh process is attempting to read historical data that has already been purged by AHM.
