test=# \d x
     Table "public.x"
 Column | Type | Modifiers 
--------+------+-----------
 y      | sig  | 
Indexes: xx gist (y sig_ops)

test=# select count(*) from x;
 count 
-------
 40000
(1 row)

test=# vacuum full analyze x;
VACUUM
test=# select sig_in('{1,2,3,4,5}'::int4[]);
                              sig_in                              
------------------------------------------------------------------
 .*****..........................................................
(1 row)

test=# select * from x where y ~>= sig_in('{1,2,3,4,5}'::int4[]);
                                y                                 
------------------------------------------------------------------
 ******.**.*..*****...***....**.****...*.*.*.....*.**.***..*..*..
 .*****.....*..............**..**......****.*....*..*.*.*.......*
 ******.*..***.*..*.**.**......*.**.*....*......*..****.....*...*
(3 rows)

test=# explain verbose select * from x where y ~>= sig_in('{1,2,3,4,5}'::int4[]);
                                   QUERY PLAN                                   
--------------------------------------------------------------------------------
    { SEQSCAN 
    :startup_cost 0.00 
    :total_cost 797.00 
    :rows 40 
    :width 8 
    :qptargetlist (
       { TARGETENTRY 
       :resdom 
          { RESDOM 
          :resno 1 
          :restype 1936051 
          :restypmod -1 
          :resname y 
          :reskey 0 
          :reskeyop 0 
          :ressortgroupref 0 
          :resjunk false 
          }
        
       :expr 
          { VAR 
          :varno 1 
          :varattno 1 
          :vartype 1936051 
          :vartypmod -1  
          :varlevelsup 0 
          :varnoold 1 
          :varoattno 1
          }
       }
    )
     
    :qpqual (
       { EXPR 
       :typeOid 16  
       :opType op 
       :oper 
          { OPER 
          :opno 1936065 
          :opid 1936063 
          :opresulttype 16 
          :opretset false 
          }
        
       :args (
          { VAR 
          :varno 1 
          :varattno 1 
          :vartype 1936051 
          :vartypmod -1  
          :varlevelsup 0 
          :varnoold 1 
          :varoattno 1
          }
        
          { EXPR 
          :typeOid 1936051  
          :opType func 
          :oper 
             { FUNC 
             :funcid 1936054 
             :funcresulttype 1936051 
             :funcretset false 
             :funcformat 0 
             }
           
          :args (
             { CONST 
             :consttype 1007 
             :constlen -1 
             :constbyval false 
             :constisnull false 
             :constvalue  44 [ 44 0 0 0 1 0 0 0 0 0 0 0 23 0 0 0 5 0 0 0 1 0 0 
             0 1 0 0 0 2 0 0 0 3 0 0 0 4 0 0 0 5 0 0 0 ] 
             }
          )
          }
       )
       }
    )
     
    :lefttree <> 
    :righttree <> 
    :extprm ()
     
    :locprm ()
     
    :initplan <> 
    :nprm 0  
    :scanrelid 1 
    }
 
 Seq Scan on x  (cost=0.00..797.00 rows=40 width=8)
   Filter: (y ~>= sig_in('{1,2,3,4,5}'::integer[]))
(94 rows)

test=#