What does vacuum have to scan to be able to reclaim space, and how many times does it need to scan to finalize ?More specifically, my VACUUM VERBOSE <table> is taking a long time and seems to be rescanning the same indexes / fields multiple times without finishing.
vacuum can only memorize one dead tuple for every 6 bytes of maintenance_work_mem. If there are more dead tuples than that, it needs to make multiple passes over the indexes.
Increase maintenance_work_mem to improve the efficiency.
Cheers,
Jeff
