Re: 7.2 is slow?

It seems that on dual PIII we are indeed faster than 7.1.3 for
small number of clients but slower for large number (~ 40)

My initial results on dual PIII/800 are as follows

7.1.3 7.2b4 7.2b4-FULL
==================================================================
./pgbench -i -p 5433
./pgbench -p 5433 -c 1 -t 100 240/251 217/223 177/181
./pgbench -p 5433 -c 5 -t 100 93/ 94 211/217 207/212
./pgbench -p 5433 -c 10 -t 100 57/ 58 145/148 160/163
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./pgbench -i -s 10 -p 5433
./pgbench -p 5433 -c 1 -t 100 171/177 162/166 169/173
./pgbench -p 5433 -c 5 -t 100 140/143 191/196 202/207
./pgbench -p 5433 -c 10 -t 100 132/135 165/168 159/163
./pgbench -p 5433 -c 25 -t 100 65/ 66 60/ 60 75/ 76
./pgbench -p 5433 -c 50 -t 100 60/ 61 43/ 43 55/ 59
./pgbench -p 5433 -c 100 -t 100 48/ 48 23/ 23 34/ 34
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One of thereasons seems to be that vacuum has chaged

after oding

psql -p 5433 -c 'vacuum full'

the result of

./pgbench -p 5433 -c 100 -t 100

was 34/34 - still ~25% slower than 7.1.3 but much better
than with non-full vacuum (which I guess is used by pgbench

The third column 7.2b4-FULL is done by running
"psql -p 5433 -c 'vacuum full'"
between each pgbench run - now the lines cross somwhere
between 25 and 50 concurrent users

One of the reasons pg is slower on last limes of my test is that
postgres is slower when vacuum is not done often enough -
on fresh db
"./pgbench -p 5433 -c 100 -t 10" gives 67/75 as result
indicating that one reason is just our non-overwriting storage manager.

I also tried to outsmart pg by running the new vacuum
concurrently, but was disappointed.

vacuuming in 'normal' psql gave me 20/20 tps and running
with nice psql gave 21/21 tps
running ./pgbench -p 5433 -c 100 -t 100 as first benchmark gave the
same result as running it after vacuum full

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PS. I hope to get single-processor results from the same computer in
about 6 hours as well (after my co-worker arrives home and can reboot
his computer to single-user)

Inxc - after you have rebooted to single-processor mode, pleas start
the postgres daemon by

su - hannu
cd db/7.2b4/
bin/pg_ctl -D data -l logfile

and ther run above pgbench commands from
cd /home/hannu/src/postgresql-7.1.3/contrib/pgbench/
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