Hi Francesco
most probabely this is due to the auto vacuum option on and if auto vacuum is on then the in condition of high transaction on database it slows the speed of the hole database.Set it off in postgres.conf and vacuum and reindex transactional tables manualy with in every two million transactions.
like
vacuum full <table name>;
reindex table <table name>;
On Fri, Jan 16, 2009 at 8:48 PM, Francesco Andreozzi <francesco.andreozzi@xxxxxxxxxxxx> wrote:
Hi all, i send this mesage because i just made a migration from my old mysql db on a more robust postgres server.
I'm using version 8.1 on a linux debian 4.0
i have a dual core XEON 2.33GHz and 2Gb of ram ... 2 disk 15k mirrored
database works good but the performance are horrible! i hope is my fault of settings.... and this message is just a help request to see whats i missing to set!
i did only few changes on a default postgresql.conf
i simply playd with shared buffer... but on a mysql to execute a simple select with an order by the time was jus 1 or 2 seconds ... on this installation the time it's about 10 seconds or more .... and if more than one query is executed at the same time the time increase!
i just add here a show all output to see if somethiong uis wrong ... i hope someone can help me ! i really would like to use postgres on this database!!
Thankyou
Francesco
begin show all command ....
-------
add_missing_from off
archive_command unset
australian_timezones off
authentication_timeout 60
autovacuum on
autovacuum_analyze_scale_factor 0.2
autovacuum_analyze_threshold 500
autovacuum_naptime 60
autovacuum_vacuum_cost_delay -1
autovacuum_vacuum_cost_limit -1
autovacuum_vacuum_scale_factor 0.4
autovacuum_vacuum_threshold 1000
backslash_quote safe_encoding
bgwriter_all_maxpages 5
bgwriter_all_percent 0.333
bgwriter_delay 200
bgwriter_lru_maxpages 5
bgwriter_lru_percent 1
block_size 8192
bonjour_name unset
check_function_bodies on
checkpoint_segments 3
checkpoint_timeout 300
checkpoint_warning 30
client_encoding UTF8
client_min_messages notice
commit_delay 0
commit_siblings 5
config_file /etc/postgresql/8.1/main/postgresql.conf
constraint_exclusion off
cpu_index_tuple_cost 0.001
cpu_operator_cost 0.0025
cpu_tuple_cost 0.01
custom_variable_classes unset
data_directory /var/lib/postgresql/8.1/main
DateStyle ISO,
db_user_namespace off
deadlock_timeout 1000
debug_pretty_print off
debug_print_parse off
debug_print_plan off
debug_print_rewritten off
default_statistics_target 10
default_tablespace unset
default_transaction_isolation read
default_transaction_read_only off
default_with_oids off
dynamic_library_path $libdir
effective_cache_size 1000
enable_bitmapscan on
enable_hashagg on
enable_hashjoin on
enable_indexscan on
enable_mergejoin on
enable_nestloop on
enable_seqscan on
enable_sort on
enable_tidscan on
escape_string_warning off
explain_pretty_print on
external_pid_file /var/run/postgresql/8.1-main.pid
extra_float_digits 0
from_collapse_limit 8
fsync on
full_page_writes on
geqo on
geqo_effort 5
geqo_generations 0
geqo_pool_size 0
geqo_selection_bias 2
geqo_threshold 12
hba_file /etc/postgresql/8.1/main/pg_hba.conf
ident_file /etc/postgresql/8.1/main/pg_ident.conf
integer_datetimes on
join_collapse_limit 8
krb_caseins_users off
krb_server_hostname unset
krb_server_keyfile FILE:/etc/postgresql/krb5.keytab
krb_srvname postgres
lc_collate en_US.UTF-8
lc_ctype en_US.UTF-8
lc_messages en_US.UTF-8
lc_monetary en_US.UTF-8
lc_numeric en_US.UTF-8
lc_time en_US.UTF-8
listen_addresses localhost
log_connections off
log_destination stderr
log_directory pg_log
log_disconnections off
log_duration off
log_error_verbosity default
log_executor_stats off
log_filename postgresql-%Y-%m-%d_%H%M%S.log
log_hostname off
log_line_prefix %t
log_min_duration_statement -1
log_min_error_statement panic
log_min_messages notice
log_parser_stats off
log_planner_stats off
log_rotation_age 1440
log_rotation_size 10240
log_statement none
log_statement_stats off
log_truncate_on_rotation off
maintenance_work_mem 16384
max_connections 100
max_files_per_process 1000
max_fsm_pages 20000
max_fsm_relations 1000
max_function_args 100
max_identifier_length 63
max_index_keys 32
max_locks_per_transaction 64
max_prepared_transactions 5
max_stack_depth 2048
password_encryption on
port 5432
pre_auth_delay 0
preload_libraries unset
random_page_cost 4
redirect_stderr off
regex_flavor advanced
search_path $user,public
server_encoding UTF8
server_version 8.1.11
shared_buffers 1000
silent_mode off
sql_inheritance on
ssl on
standard_conforming_strings off
statement_timeout 0
stats_block_level off
stats_command_string off
stats_reset_on_server_start off
stats_row_level on
stats_start_collector on
superuser_reserved_connections 2
syslog_facility LOCAL0
syslog_ident postgres
tcp_keepalives_count 0
tcp_keepalives_idle 0
tcp_keepalives_interval 0
temp_buffers 1000
TimeZone localtime
trace_notify off
trace_sort off
transaction_isolation read
transaction_read_only off
transform_null_equals off
unix_socket_directory /var/run/postgresql
unix_socket_group unset
unix_socket_permissions 511
vacuum_cost_delay 0
vacuum_cost_limit 200
vacuum_cost_page_dirty 20
vacuum_cost_page_hit 1
vacuum_cost_page_miss 10
wal_buffers 8
wal_sync_method fdatasync
work_mem 1024
zero_damaged_pages off
-----
end show all
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Brahma Prakash Tiwari
Database Administrator
iBoss Tech Solution Noida
