Re: the right time to vacuum database? - Mailing list pgsql-admin
From | Charles.Hou |
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Subject | Re: the right time to vacuum database? |
Date | |
Msg-id | 1181089690.963738.260660@n15g2000prd.googlegroups.com Whole thread Raw |
In response to | Re: the right time to vacuum database? (Andrew Sullivan <ajs@crankycanuck.ca>) |
Responses |
Re: the right time to vacuum database?
|
List | pgsql-admin |
On 6 5 , 9 25 , a...@crankycanuck.ca (Andrew Sullivan) wrote: > On Tue, Jun 05, 2007 at 03:33:09AM -0700, Charles.Hou wrote: > > how can i know that it's the time to vacuumdb? i set the crontab to > > vacuumdb 3 times in one day. because my database size increase from > > 440MB to 460MB in 8 hours. > > You haven't told us enough. What's the churn on the database, to > begin with? That's only 20M. If you replace approximately 20M in 8 > hours, then it might be that the FSM is working perfectly, and this > is the overhead that is reasonable to keep around to allow your > database to work perfectly. > > Also, have you looked into autovacuum? It might take some of the > guesswork out of this. > > Finally, I expect that most of your churn is in particular tables. > Those are the ones you want to vacuum frequently. The rest of them > aren't that interesting. The way to learn about this is to use > VACUUM VERBOSE, which will give you information about how many pages > it is recovering. > > A > > -- > Andrew Sullivan | a...@crankycanuck.ca > "The year's penultimate month" is not in truth a good way of saying > November. > --H.W. Fowler > > ---------------------------(end of broadcast)--------------------------- > TIP 2: Don't 'kill -9' the postmaster the version of PostgreSQL is 8.1.3 on i686-redhat-linux-gnu,compiled by GCC 3.4.4 (Red-Hat 3.4.4-2) Client connected: about 100 pc, 1 pc with 1 connection at least, the max is 4 connections 194 tables on the database, and some of the tables always executed the update/insert command . i also set the autovacuum to enable. today, the database size is 497MB. 497-440MB=57MB, 57 MB have been increased in 18 hours. what's wrong with my PostgreSql Server? postgresql.conf #--------------------------------------------------------------------------- # CONNECTIONS AND AUTHENTICATION #--------------------------------------------------------------------------- # - Connection Settings - #listen_addresses = 'localhost' # what IP address(es) to listen on; listen_addresses = '*' # what IP address(es) to listen on; # comma-separated list of addresses; # defaults to 'localhost', '*' = all #port = 5432 max_connections = 1000 # note: increasing max_connections costs ~400 bytes of shared memory per # connection slot, plus lock space (see max_locks_per_transaction). You # might also need to raise shared_buffers to support more connections. superuser_reserved_connections = 2 #unix_socket_directory = '' #unix_socket_group = '' #unix_socket_permissions = 0777 # octal #bonjour_name = '' # defaults to the computer name # - Security & Authentication - #authentication_timeout = 60 # 1-600, in seconds #ssl = off #password_encryption = on #db_user_namespace = off # Kerberos #krb_server_keyfile = '' #krb_srvname = 'postgres' #krb_server_hostname = '' # empty string matches any keytab entry #krb_caseins_users = off # - TCP Keepalives - # see 'man 7 tcp' for details #tcp_keepalives_idle = 0 # TCP_KEEPIDLE, in seconds; # 0 selects the system default #tcp_keepalives_interval = 0 # TCP_KEEPINTVL, in seconds; # 0 selects the system default #tcp_keepalives_count = 0 # TCP_KEEPCNT; # 0 selects the system default #--------------------------------------------------------------------------- # RESOURCE USAGE (except WAL) #--------------------------------------------------------------------------- # - Memory - shared_buffers = 2000 # min 16 or max_connections*2, 8KB each temp_buffers = 1000 # min 100, 8KB each #max_prepared_transactions = 5 # can be 0 or more # note: increasing max_prepared_transactions costs ~600 bytes of shared memory # per transaction slot, plus lock space (see max_locks_per_transaction). work_mem = 1024 # min 64, size in KB maintenance_work_mem = 16384 # min 1024, size in KB #max_stack_depth = 2048 # min 100, size in KB # - Free Space Map - #max_fsm_pages = 20000 # min max_fsm_relations*16, 6 bytes each max_fsm_pages = 300000 # min max_fsm_relations*16, 6 bytes each max_fsm_relations = 1000 # min 100, ~70 bytes each #max_fsm_relations = 2000 # min 100, ~70 bytes each # - Kernel Resource Usage - #max_files_per_process = 1000 # min 25 #preload_libraries = '' # - Cost-Based Vacuum Delay - #vacuum_cost_delay = 0 # 0-1000 milliseconds vacuum_cost_delay = 200 # 0-1000 milliseconds #vacuum_cost_page_hit = 1 # 0-10000 credits vacuum_cost_page_hit = 6 # 0-10000 credits #vacuum_cost_page_miss = 10 # 0-10000 credits #vacuum_cost_page_dirty = 20 # 0-10000 credits #vacuum_cost_limit = 200 # 0-10000 credits vacuum_cost_limit = 100 # 0-10000 credits # - Background writer - #bgwriter_delay = 200 # 10-10000 milliseconds between rounds #bgwriter_lru_percent = 1.0 # 0-100% of LRU buffers scanned/round #bgwriter_lru_maxpages = 5 # 0-1000 buffers max written/round #bgwriter_all_percent = 0.333 # 0-100% of all buffers scanned/round #bgwriter_all_maxpages = 5 # 0-1000 buffers max written/round #--------------------------------------------------------------------------- # WRITE AHEAD LOG #--------------------------------------------------------------------------- # - Settings - #fsync = on # turns forced synchronization on or off #wal_sync_method = fsync # the default is the first option # supported by the operating system: # open_datasync # fdatasync # fsync # fsync_writethrough # open_sync #full_page_writes = on # recover from partial page writes #wal_buffers = 8 # min 4, 8KB each #commit_delay = 0 # range 0-100000, in microseconds #commit_siblings = 5 # range 1-1000 # - Checkpoints - #checkpoint_segments = 3 # in logfile segments, min 1, 16MB each #checkpoint_timeout = 300 # range 30-3600, in seconds #checkpoint_warning = 30 # in seconds, 0 is off # - Archiving - archive_command = '' # command to use to archive a logfile # segment #Added, IChang, 11/28/2006 for restore #archive_command = 'cp -f %p /home/csc/DB_HotBackup/archives/%f' #--------------------------------------------------------------------------- # QUERY TUNING #--------------------------------------------------------------------------- # - Planner Method Configuration - enable_bitmapscan = on enable_hashagg = on enable_hashjoin = on enable_indexscan = on enable_mergejoin = on enable_nestloop = on enable_seqscan = off enable_sort = on enable_tidscan = on # - Planner Cost Constants - #effective_cache_size = 1000 # typically 8KB each effective_cache_size = 1300 # 2/3 of Ram random_page_cost = 4 # units are one sequential page fetch # cost #cpu_tuple_cost = 0.01 # (same) #cpu_index_tuple_cost = 0.001 # (same) #cpu_operator_cost = 0.0025 # (same) # - Genetic Query Optimizer - #geqo = on #geqo_threshold = 12 #geqo_effort = 5 # range 1-10 #geqo_pool_size = 0 # selects default based on effort #geqo_generations = 0 # selects default based on effort #geqo_selection_bias = 2.0 # range 1.5-2.0 # - Other Planner Options - #default_statistics_target = 10 # range 1-1000 #constraint_exclusion = off #from_collapse_limit = 8 #join_collapse_limit = 8 # 1 disables collapsing of explicit # JOINs #--------------------------------------------------------------------------- # ERROR REPORTING AND LOGGING #--------------------------------------------------------------------------- # - Where to Log - #log_destination = 'syslog' # Valid values are combinations of # stderr, syslog and eventlog, # depending on platform. # This is used when logging to stderr: redirect_stderr = on # Enable capturing of stderr into log #redirect_stderr = off # Enable capturing of stderr into log # files # These are only used if redirect_stderr is on: log_directory = 'pg_log' # Directory where log files are written # Can be absolute or relative to PGDATA #log_filename = 'postgresql-%Y-%m-%d_%H%M%S.log' # Log file name pattern. log_filename = 'postgresql-%a.log' # Log file name pattern. # Can include strftime() escapes log_truncate_on_rotation = on # If on, any existing log file of the same # name as the new log file will be # truncated rather than appended to. But # such truncation only occurs on # time-driven rotation, not on restarts # or size-driven rotation. Default is # off, meaning append to existing files # in all cases. log_rotation_age = 1440 # Automatic rotation of logfiles will # happen after so many minutes. 0 to # disable. log_rotation_size = 0 # Automatic rotation of logfiles will # happen after so many kilobytes of log # output. 0 to disable. # These are relevant when logging to syslog: #syslog_facility = 'LOCAL0' #syslog_ident = 'postgres' # - When to Log - #client_min_messages = notice # Values, in order of decreasing detail: # debug5 # debug4 # debug3 # debug2 # debug1 # log # notice # warning # error #log_min_messages = notice # Values, in order of decreasing detail: # debug5 # debug4 # debug3 # debug2 # debug1 # info # notice # warning # error # log # fatal # panic #log_error_verbosity = default # terse, default, or verbose messages #log_min_error_statement = panic # Values in order of increasing severity: # debug5 # debug4 # debug3 # debug2 # debug1 # info # notice # warning # error # panic(off) #log_min_duration_statement = -1 # -1 is disabled, 0 logs all statements # and their durations, in milliseconds. #silent_mode = on # DO NOT USE without syslog or # redirect_stderr # - What to Log - #debug_print_parse = off #debug_print_rewritten = off #debug_print_plan = off #debug_pretty_print = off log_connections = off #log_connections = on log_disconnections = off #log_disconnections = on #log_duration = off log_duration = on #log_line_prefix = '' # Special values: #log_line_prefix = 'user=%u,db=%d' log_line_prefix = '%t %p ' # Special values: # %u = user name # %d = database name # %r = remote host and port # %h = remote host # %p = PID # %t = timestamp (no milliseconds) # %m = timestamp with milliseconds # %i = command tag # %c = session id # %l = session line number # %s = session start timestamp # %x = transaction id # %q = stop here in non-session # processes # %% = '%' # e.g. '<%u%%%d> ' #log_statement = 'none' # none, mod, ddl, all #log_statement = 'all' # none, mod, ddl, all log_statement = 'mod' # none, mod, ddl, all #log_hostname = off #--------------------------------------------------------------------------- # RUNTIME STATISTICS #--------------------------------------------------------------------------- # - Statistics Monitoring - #log_parser_stats = off #log_planner_stats = off #log_executor_stats = off #log_statement_stats = off # - Query/Index Statistics Collector - stats_start_collector = on #stats_command_string = off #stats_block_level = off #stats_row_level = off stats_row_level = on #stats_reset_on_server_start = off #--------------------------------------------------------------------------- # AUTOVACUUM PARAMETERS #--------------------------------------------------------------------------- #autovacuum = off # enable autovacuum subprocess? autovacuum = on # enable autovacuum subprocess? autovacuum_naptime = 20 # time between autovacuum runs, in secs #autovacuum_vacuum_threshold = 1000 # min # of tuple updates before autovacuum_vacuum_threshold = 1 # min # of tuple updates before # vacuum #autovacuum_analyze_threshold = 500 # min # of tuple updates before autovacuum_analyze_threshold = 1 # min # of tuple updates before # analyze #autovacuum_vacuum_scale_factor = 0.4 # fraction of rel size before autovacuum_vacuum_scale_factor = 0.1 # fraction of rel size before # vacuum autovacuum_analyze_scale_factor = 0.2 # fraction of rel size before #autovacuum_analyze_scale_factor = 1 # fraction of rel size before # analyze #autovacuum_vacuum_cost_delay = -1 # default vacuum cost delay for # autovac, -1 means use # vacuum_cost_delay #autovacuum_vacuum_cost_limit = -1 # default vacuum cost limit for # autovac, -1 means use # vacuum_cost_limit #--------------------------------------------------------------------------- # CLIENT CONNECTION DEFAULTS #--------------------------------------------------------------------------- # - Statement Behavior - #search_path = '$user,public' # schema names #default_tablespace = '' # a tablespace name, '' uses # the default #check_function_bodies = on #default_transaction_isolation = 'read committed' #default_transaction_read_only = off #statement_timeout = 0 # 0 is disabled, in milliseconds # - Locale and Formatting - #datestyle = 'iso, mdy' #timezone = unknown # actually, defaults to TZ # environment setting #australian_timezones = off #extra_float_digits = 0 # min -15, max 2 #client_encoding = sql_ascii # actually, defaults to database client_encoding = BIG5 # actually, defaults to database # encoding # These settings are initialized by initdb -- they might be changed #lc_messages = 'zh_TW.big5' # locale for system error message lc_messages = 'C' # locale for system error message # strings #lc_monetary = 'zh_TW.big5' # locale for monetary formatting lc_monetary = 'C' # locale for monetary formatting #lc_numeric = 'zh_TW.big5' # locale for number formatting lc_numeric = 'C' # locale for number formatting #lc_time = 'zh_TW.big5' # locale for time formatting lc_time = 'C' # locale for time formatting # - Other Defaults - #explain_pretty_print = on #dynamic_library_path = '$libdir' #--------------------------------------------------------------------------- # LOCK MANAGEMENT #--------------------------------------------------------------------------- #deadlock_timeout = 1000 # in milliseconds #max_locks_per_transaction = 64 # min 10 # note: each lock table slot uses ~220 bytes of shared memory, and there are # max_locks_per_transaction * (max_connections + max_prepared_transactions) # lock table slots. #--------------------------------------------------------------------------- # VERSION/PLATFORM COMPATIBILITY #--------------------------------------------------------------------------- # - Previous Postgres Versions - #add_missing_from = off #regex_flavor = advanced # advanced, extended, or basic #sql_inheritance = on #default_with_oids = off #escape_string_warning = off # - Other Platforms & Clients - #transform_null_equals = off #--------------------------------------------------------------------------- # CUSTOMIZED OPTIONS #--------------------------------------------------------------------------- #custom_variable_classes = '' # list of custom variable class names
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