Performance of Bit String

Hi,<br /><br />I tried to store a BitString of length 2 million in a Postgres table (see code below), but it did not
completeeven in 3 mins and then I cancelled it. Surprisingly, it only took few seconds when BitString was of length
500K.Is there any restriction of length of BitString or am I missing something here? <br /><br />create table
bit_test(<br/> id smallint,<br /> memset bit(200000)<br /> ) ;<br /><br />DECLARE<br /> memset bit varying:= B'0';<br
/>BEGIN<br/> --PERFORM memset;<br /> FOR i In 1..2000000 LOOP<br /> memset := (memset || B'1') ; -- (B'1' <<
i);<br/> END LOOP;<br /><br /> INSERT INTO bit_test VALUES(1,B'1',memset :: bit(2000000));<br /><br />RETURN
bit_length(memset);<br/>END;<br /><br /><br />Thanks,<br />Rupendra