On Mon, Apr 9, 2018 at 6:56 PM, Alexandre Arruda <adaldeia@xxxxxxxxx> wrote: > (... and all other indexes returns null too) > > I tried with bt_index_check too. Same results. That's interesting, because it tells me that you have a table that appears to not be corrupt, despite the CLUSTER error. Also, the error itself comes from sanity checking added to MultiXact freezing fairly recently, in commit 699bf7d0. You didn't say anything about regular VACUUM being broken. Do you find that it works without any apparent issue? I have a suspicion that this could be a subtle bug in CLUSTER/freezing. The only heap_freeze_tuple() caller is code used by CLUSTER, so it's not that hard to imagine a MultiXact freezing bug that is peculiar to CLUSTER. Though I haven't thought about it in much detail. -- Peter Geoghegan