drop table if exists block:numblocks;
create table block:numblocks (col1 integer not null, col2 text not null);
insert into block:numblocks
select generate_series(1,8192*:numblocks/(48+:filler))
,repeat('a', :filler);
create unique index idx_block:numblocks on block:numblocks (col1);
analyze block:numblocks;
select pg_relation_size('block' || (:numblocks)::text);
\timing 
\pset pager off
explain
select * from block:numblocks where col1 = :pkval;
select * from block:numblocks where col1 = :pkval;
select * from block:numblocks where col1 = :pkval;
select * from block:numblocks where col1 = :pkval;
select * from block:numblocks where col1 = :pkval;
select * from block:numblocks where col1 = :pkval;
select * from block:numblocks where col1 = :pkval;

set enable_seqscan = off;

explain
select * from block:numblocks where col1 = :pkval;
select * from block:numblocks where col1 = :pkval;
select * from block:numblocks where col1 = :pkval;
select * from block:numblocks where col1 = :pkval;