Re: 7.4beta2 vs 7.3.3 - Mailing list pgsql-hackers

Tom Lane wrote:
> Gaetano Mendola <mendola@bigfoot.com> writes:
>
>>Tom Lane wrote:
>>
>>>Hm, it sure looks to be exactly the same plan.  The performance
>>>difference seems to be just that the seqscans are faster.  I surmise
>>>that in the 7.3 database you had a lot of dead rows, or at least a lot
>>>of free space.  Possibly you need to vacuum more often to keep down the
>>>amount of junk in the tables.
>
>
>>The two databases were created from scratch and the first
>>operation on it ( after a vacuum analyze ) was just that query.
>
>
> Y'know, I'd love to think that 7.4 is 2x faster than 7.3 on seqscanning,
> but I just can't believe that.  We didn't do anything that could account
> for such a speedup.  So there's got to be some inconsistency in your
> test conditions.

The machine is the same, the disk too, the main values in the
configuration file are the same ( I put the confs in attachment ).
I was alo able to remove the useless column on that tables, and I
put the dump here:

http://212.198.37.110

The select take long:

Postgres7.3.3:  average 4000 ms
Postgres7.4b2:  average 2600 ms

you can experiment your self with the dump that I gave you

Regards
Gaetano Mendola

tcpip_socket = true
max_connections = 128

shared_buffers = 13000        # I'm running two postgres server
max_fsm_relations = 1000    # min 10, fsm is free space map, ~40 bytes
max_fsm_pages = 2000000
max_locks_per_transaction = 64    # min 10

wal_buffers = 2000

sort_mem = 32768
vacuum_mem = 32768

default_statistics_target = 1000

server_min_messages = debug2

log_connections = true
log_pid = true
log_statement = true
log_duration = true
log_timestamp = true

syslog = 2
syslog_facility = 'LOCAL0'
syslog_ident = 'postgres'

stats_start_collector = true
stats_reset_on_server_start = true
stats_command_string = true
stats_row_level = true
stats_block_level = true

LC_MESSAGES = 'en_US.UTF-8'
LC_MONETARY = 'en_US.UTF-8'
LC_NUMERIC = 'en_US.UTF-8'
LC_TIME = 'en_US.UTF-8'

tcpip_socket = true
max_connections = 128

shared_buffers = 13000
sort_mem = 32768
vacuum_mem = 32768

max_fsm_pages = 2000000
max_fsm_relations = 1000

wal_buffers = 2000

default_statistics_target = 1000

syslog = 2
syslog_facility = 'LOCAL0'
syslog_ident = 'postgres'

log_min_messages = debug2

log_connections = true
log_duration = true
log_pid = true
log_statement = true
log_timestamp = true
log_hostname = false
log_source_port = true



stats_start_collector = true
stats_command_string = true
stats_block_level = true
stats_row_level = true
stats_reset_on_server_start = true


lc_messages = 'en_US.UTF-8'        # locale for system error message strings
lc_monetary = 'en_US.UTF-8'        # locale for monetary formatting
lc_numeric = 'en_US.UTF-8'        # locale for number formatting
lc_time = 'en_US.UTF-8'            # locale for time formatting