>>>>> "PS" == Pavel Stehule <pavel.steh...@gmail.com> writes:

    PS> please, send explain result

For ~ 10 million rows table:

  explain declare c cursor for select * from foo2 order by value;
                                QUERY PLAN                              
  ----------------------------------------------------------------------
   Sort  (cost=1829429.20..1854429.20 rows=9999999 width=10)
     Sort Key: value
     ->  Seq Scan on foo2  (cost=0.00..154049.99 rows=9999999 width=10)
  (3 rows)

For ~ 1 million rows table, containing the first million rows from foo2
(`value' column contains random integer data):

  explain declare c cursor for select * from foo order by value;
                                      QUERY PLAN                                
     
  
-----------------------------------------------------------------------------------
   Index Scan using foo_value_idx on foo  (cost=0.00..47604.02 rows=999999 
width=10)
  (1 row)

When seqscan is disabled for the 10 million rows table:

  set enable_seqscan = off;
  explain declare c cursor for select * from foo2 order by value;
                                         QUERY PLAN                             
           
  
-----------------------------------------------------------------------------------------
   Index Scan using foo2_value_idx on foo2  (cost=0.00..32220140.73 
rows=9999999 width=10)
  (1 row)

Regards,
Milan Zamazal


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