On 17 October 2011 02:01, Scott Marlowe
<scott.marlowe@gmail.com> wrote:
On Sun, Oct 16, 2011 at 2:41 PM, Szymon Guz <
mabewlun@gmail.com> wrote:
> Hi,
> just a couple of questions:
> will there be an index bloat if I have:
> - a serial column and only add rows to the table?
> - a text column and I only add rows to the table?
> For the serial column the numbers are only incremented, for the text column
> I add random strings.
Hi Scott,
if there is no bloat, how could you explain this:
Simple test:
CREATE TABLE test (
id text primary key,
category_id text not null
);
CREATE INDEX i_category ON test (category_id);
I make 500k inserts in one transaction using a python script.
For the random text I use random uuid from the function:
uuid.uuid4()
After those inserts I create another index:
CREATE INDEX i_new ON test (category_id);
select
pg_size_pretty(pg_relation_size('i_category')),
pg_size_pretty(pg_relation_size('i_new'))
;
Results:
'37 MB';'28 MB'
regards
Szymon
