Hi all, I suspect this problem/bug has been dealt with already, but I couldn't find anything in the mail archives.
I'm using postgres 7.3, and I managed to recreate the problem using the attached files. The database structure is in slow_structure.sql After creating the database, using this script, I ran run_before_load__fast.sql Then I created a load file using create_loadfile.sh (It creates a file called load.sql) I timed the loading of this file, and it loaded in 1 min 11.567 sec Then I recreated the database from slow_structure.sql, ran run_before_load__slow.sql, and then loaded the same load.sql and it took 3 min 51.293 sec which is about 6 times slower. I tried the same thing on postgres 8.0.0 to see if it does the same thing, but there it was consistently slow : 3 min 31.367 sec The only way I got the load.sql to load fast on postgres 8.0.0, was by not creating any of the foreign key constraints that point to the "main" table, and then enabling them afterwards. This gave me the fastest time overall : 1 min 4.911 sec My problem is that on the postgres 7.3.4 database I'm working with, a load process that used to take 40 minutes, now takes 4 hours, because of 3 rows data being loaded into a table (similar in setup to the "main" table in the example) before the indexes were created. (This happens automatically when you dump and re-import the database (7.3.4)) Is there a way to get it to load fast again on the 7.3 database without dropping the foreign key constraints (After running run_before_load_slow.sql) ? And, if someone knows off-hand, what's happening here? TIA Kind Regards Stefan
#!/bin/bash
for x in one two three four five six seven eight nine ten
do
for y in eleven twelve thirteen fourteen fifteen sixteen seventeen eighteen nineteen twenty
do
for z in `seq 1 100`
do
echo "insert into main (c_text,d_text) values ('${x}','${y}');" >> load.sql
echo "insert into a(id) values (currval('public.main_id_seq'::text));" >> load.sql
echo "insert into b(id) values (currval('public.main_id_seq'::text));" >> load.sql
echo "insert into e(id) values (currval('public.main_id_seq'::text));" >> load.sql
echo "insert into f(id) values (currval('public.main_id_seq'::text));" >> load.sql
echo "insert into g(id) values (currval('public.main_id_seq'::text));" >> load.sql
echo "insert into h(id) values (currval('public.main_id_seq'::text));" >> load.sql
done
done
done
run_before_load__fast.sql
Description: Binary data
run_before_load__slow.sql
Description: Binary data
slow_structure.sql
Description: Binary data
---------------------------(end of broadcast)---------------------------
TIP 9: the planner will ignore your desire to choose an index scan if your
joining column's datatypes do not match
