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RES: select on 1milion register = 6s

From: "Bruno Rodrigues Siqueira" <bruno(at)ravnus(dot)com>
To: 'Hervé Piedvache' <bill(dot)footcow(at)gmail(dot)com>,<pgsql-performance(at)postgresql(dot)org>
Subject: RES: select on 1milion register = 6s
Date: 2007-07-28 22:40:48
Message-ID: 002b01c7d168$58b7c130$e900a8c0@brunolaptop (view raw or flat)
Thread:
Lists: pgsql-performance
Yes.



Look this... and please, tell me if you can help me...


Thanks

Query

EXPLAIN
ANALYZE
select 
       to_char(data_encerramento,'mm/yyyy')  as opcoes_mes, 
       to_char(data_encerramento,'yyyy-mm') as ordem from detalhamento_bas
where

to_char( data_encerramento ,'yyyy-mm') 
between   '2006-12' and  '2007-01'

GROUP BY opcoes_mes, ordem
ORDER BY ordem DESC





	QUERY RESULT

QUERY PLAN
Sort  (cost=11449.37..11449.40 rows=119 width=8) (actual
time=14431.537..14431.538 rows=2 loops=1)
  Sort Key: to_char(data_encerramento, 'yyyy-mm'::text)
  ->  HashAggregate  (cost=11448.79..11448.96 rows=119 width=8) (actual
time=14431.521..14431.523 rows=2 loops=1)
        ->  Index Scan using detalhamento_bas_idx3003 on detalhamento_bas
(cost=0.00..11442.95 rows=11679 width=8) (actual time=0.135..12719.155
rows=2335819 loops=1)
              Index Cond: ((to_char(data_encerramento, 'yyyy-mm'::text) >=
'2006-12'::text) AND (to_char(data_encerramento, 'yyyy-mm'::text) <=
'2007-01'::text))
Total runtime: 14431.605 ms	








	SERVER
	 	  DELL PowerEdge 2950
		  XEON Quad-Core 3.0Ghz
		  4Gb RAM
		  Linux CentOS 5.0 64-bits





     Postgres 8.1.4




     Postgresql.conf


# -----------------------------
# PostgreSQL configuration file
# -----------------------------
#
# This file consists of lines of the form:
#
#   name = value
#
# (The '=' is optional.) White space may be used. Comments are introduced #
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settings shown in this file represent the default values.
#
# Please note that re-commenting a setting is NOT sufficient to revert it #
to the default value, unless you restart the postmaster.
#
# Any option can also be given as a command line switch to the # postmaster,
e.g. 'postmaster -c log_connections=on'. Some options # can be changed at
run-time with the 'SET' SQL command.
#
# This file is read on postmaster startup and when the postmaster # receives
a SIGHUP. If you edit the file on a running system, you have # to SIGHUP the
postmaster for the changes to take effect, or use # "pg_ctl reload". Some
settings, such as listen_addresses, require # a postmaster shutdown and
restart to take effect.


#---------------------------------------------------------------------------
# FILE LOCATIONS
#---------------------------------------------------------------------------

# The default values of these variables are driven from the -D command line
# switch or PGDATA environment variable, represented here as ConfigDir.

#data_directory = 'ConfigDir'		# use data in another directory
#hba_file = 'ConfigDir/pg_hba.conf'	# host-based authentication file
#ident_file = 'ConfigDir/pg_ident.conf'	# IDENT configuration file

# If external_pid_file is not explicitly set, no extra pid file is written.
#external_pid_file = '(none)'		# write an extra pid file


#---------------------------------------------------------------------------
# CONNECTIONS AND AUTHENTICATION
#---------------------------------------------------------------------------

# - Connection Settings -

listen_addresses = '*'		# what IP address(es) to listen on; 
					# comma-separated list of addresses;
					# defaults to 'localhost', '*' = all
#port = 5432 max_connections = 10 # 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 = 50000			# 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 = 3145728			# min 64, size in KB
maintenance_work_mem = 4194304		# min 1024, size in KB
max_stack_depth = 2048			# min 100, size in KB

# - Free Space Map -

max_fsm_pages = 208000			# min max_fsm_relations*16, 6 bytes
each
max_fsm_relations = 10000		# min 100, ~70 bytes each

# - Kernel Resource Usage -

#max_files_per_process = 1000		# min 25
#preload_libraries = ''

# - Cost-Based Vacuum Delay -

vacuum_cost_delay = 50			# 0-1000 milliseconds
#vacuum_cost_page_hit = 1		# 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

# - Background writer -

bgwriter_delay = 200			# 10-10000 milliseconds between
rounds
bgwriter_lru_percent = 20.0		# 0-100% of LRU buffers
scanned/round
bgwriter_lru_maxpages = 100		# 0-1000 buffers max written/round
bgwriter_all_percent = 3		# 0-100% of all buffers
scanned/round
bgwriter_all_maxpages = 600		# 0-1000 buffers max written/round


#---------------------------------------------------------------------------
# WRITE AHEAD LOG
#---------------------------------------------------------------------------

# - Settings -

fsync = off				# 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 = off			# recover from partial page writes
wal_buffers = 2300			# min 4, 8KB each
commit_delay = 10			# range 0-100000, in microseconds
#commit_siblings = 5			# range 1-1000

# - Checkpoints -

checkpoint_segments = 256		# in logfile segments, min 1, 16MB
each
checkpoint_timeout = 300		# range 30-3600, in seconds
checkpoint_warning = 99		# in seconds, 0 is off

# - Archiving -

#archive_command = ''			# command to use to archive a
logfile 
					# segment


#---------------------------------------------------------------------------
# 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 = on
enable_sort = on
enable_tidscan = on

# - Planner Cost Constants -

effective_cache_size = 41943040		# typically 8KB each
random_page_cost = 1			# units are one sequential page
fetch 
					# cost
cpu_tuple_cost = 0.001			# (same)
cpu_index_tuple_cost = 0.0005		# (same)
cpu_operator_cost = 0.00025		# (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 = on
#from_collapse_limit = 8
join_collapse_limit = 1		# 1 disables collapsing of explicit 
					# JOINs


#---------------------------------------------------------------------------
# ERROR REPORTING AND LOGGING
#---------------------------------------------------------------------------

# - Where to Log -

#log_destination = 'stderr'		# 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 
					# 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-%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 = off			# 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_disconnections = off
#log_duration = off
#log_line_prefix = ''			# 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_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 = off
#stats_command_string = off
#stats_block_level = off
#stats_row_level = off
#stats_reset_on_server_start = off


#---------------------------------------------------------------------------
# AUTOVACUUM PARAMETERS
#---------------------------------------------------------------------------

autovacuum = on			# enable autovacuum subprocess?
#autovacuum_naptime = 60		# time between autovacuum runs, in
secs
#autovacuum_vacuum_threshold = 1000	# min # of tuple updates before
					# vacuum
#autovacuum_analyze_threshold = 500	# min # of tuple updates before 
					# analyze
#autovacuum_vacuum_scale_factor = 0.4	# fraction of rel size before 
					# vacuum
#autovacuum_analyze_scale_factor = 0.2	# 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, dmy'
#timezone = unknown			# actually, defaults to TZ 
					# environment setting
#australian_timezones = off
#extra_float_digits = 0			# min -15, max 2
client_encoding = LATIN1		# actually, defaults to database
					# encoding

# These settings are initialized by initdb -- they might be changed
lc_messages = 'pt_BR.ISO-8859-1'			# locale for system
error message 
					# strings
lc_monetary = 'pt_BR.ISO-8859-1'			# locale for
monetary formatting
lc_numeric = 'pt_BR.ISO-8859-1'			# locale for number
formatting
lc_time = 'pt_BR.ISO-8859-1'				# 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
#backslash_quote = safe_encoding	# on, off, or safe_encoding
#default_with_oids = off
#escape_string_warning = off
#regex_flavor = advanced		# advanced, extended, or basic
#sql_inheritance = on

# - Other Platforms & Clients -

#transform_null_equals = off


#---------------------------------------------------------------------------
# CUSTOMIZED OPTIONS
#---------------------------------------------------------------------------

#custom_variable_classes = ''		# list of custom variable class
names







-----Mensagem original-----
De: Hervé Piedvache [mailto:bill(dot)footcow(at)gmail(dot)com] 
Enviada em: sábado, 28 de julho de 2007 16:57
Para: pgsql-performance(at)postgresql(dot)org
Cc: Bruno Rodrigues Siqueira
Assunto: Re: [PERFORM] select on 1milion register = 6s

Do you have analyzed your table before doing this ?

Le samedi 28 juillet 2007, Bruno Rodrigues Siqueira a écrit :
> Friends,
>
>
>
>
>
>
>
>             Who can help me? My SELECT in a base with 1 milion register,
> using  expression index = 6seconds.
>
>
>
>
>
> Please, I don't  know how to makes it better.
>
>
>
>
>
> Thanks



-- 
Hervé Piedvache


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