Re: [**EXTERNAL**] Re: [pgsql-admin] "Soft-hitting" the 1600 column limit

​A cursory skim of cluster.c, plus general reasoning, leads me to think that the extent of the smarts of the table rewrite (for vacuum full at least, not cluster) is to evaluate headers for visibility and omit copying the physical tuples to the new heap.  The contents of each tuple are otherwise copied as-is (except toast pointers...).  So, yes, the variant column structures would indeed survive vacuum full and clustering operations.  There isn't any motivation to do more - a 1600​ column limit, even with dropped columns counted, is not unreasonable - and doing more would making an already expensive operation even more expensive (and the risk of serious data-losing bugs in the first release is scary).