Re: tuning tips, speed problem

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(dot)andreozzi(at)gamestorm(dot)it> 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