sql: index creation on 1.3 billion row table taking 5 days

[vivekmenezes]

select count(1) from t;
   count
+------------+
 1393445658
(1 row)

Time: 7m25.905025076s

on the above table split across 14K ranges an index backfill takes around 5 days on the 19.1 branch

with 14K ranges this is approximately on an average 100K rows per range or 100K index entries per range.
We currently make index SSTs by range. I'm expecting #36192 to help but we need to verify that it indeed solves this problem

[vivekmenezes]

fixed by #36693 which significantly improves the performance of index backfill. The PR will be put into 19.1.1