> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > I loaded 10,000,000 rows into CREATE TABLE test (x INTEGER); Table is
> > 400MB and index is 160MB.
>
> > With index on the single in4 column, I got:
> > 78 seconds for a vacuum
> > 121 seconds for vacuum after deleting a single row
> > 662 seconds for vacuum after deleting the entire table
>
> > With no index, I got:
> > 43 seconds for a vacuum
> > 43 seconds for vacuum after deleting a single row
> > 43 seconds for vacuum after deleting the entire table
>
> > I find this quite interesting.
>
> How long does it take to create the index on your setup --- ie,
> if vacuum did a drop/create index, would it be competitive?
OK, new timings with -F enabled:
index no index519 same load 247 " first vacuum40 " other vacuums1222 X index creation90
X first vacuum80 X other vacuums<1 90 delete one row121 38 vacuum after delete 1 row346 344
deleteall rows440 44 first vacuum20 <1 other vacuums(index is still same size)
Conclusions:
o indexes never get smallero drop/recreate index is slower than vacuum of indexes
What other conclusions can be made?
-- Bruce Momjian | http://www.op.net/~candle pgman@candle.pha.pa.us | (610)
853-3000+ If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill,
Pennsylvania19026