Aumentar el desempeño del servidor

Hola,

Estoy con un problema grave de desempeño del servidor.

Características del servidor:
procesador: 2 processadores Xeon de 3.8 GHz
memoria.....: 5 Gb
sistema......: debian linux
usuarios.....: aproximadamente 140
PostgreSql versión 8.2.4
El vaccum está programado para ser ejecutado todo domingo.

Agradezco cualquier ajuda.

Esta es el arquivo Postgres.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
# with '#' anywhere on a line. The complete list of option names and
# allowed values can be found in the PostgreSQL documentation. The
# commented-out 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 server.
#
# Any option can also be given as a command line switch to the server,
# e.g., 'postgres -c log_connections=on'. Some options can be changed at
# run-time with the 'SET' SQL command.
#
# This file is read on server startup and when the server receives a
# SIGHUP. If you edit the file on a running system, you have to SIGHUP the
# server for the changes to take effect, or use "pg_ctl reload". Some
# settings, which are marked below, require a server shutdown and restart
# to take effect.
#
# Memory units: kB = kilobytes MB = megabytes GB = gigabytes
# Time units: ms = milliseconds s = seconds min = minutes h = hours d =
days

#---------------------------------------------------------------------------
# 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
# (change requires restart)
hba_file = '/etc/postgresql/8.2/main/pg_hba.conf' # host-based
authentication file
# (change requires restart)
ident_file = '/etc/postgresql/8.2/main/pg_ident.conf' # ident configuration
file
# (change requires restart)

# If external_pid_file is not explicitly set, no extra PID file is written.
external_pid_file = '/var/run/postgresql/8.2-main.pid' # write an extra PID
file
# (change requires restart)

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

# - Connection Settings -

listen_addresses = '*' # what IP address(es) to listen on;
# comma-separated list of addresses;
# defaults to 'localhost', '*' = all
# (change requires restart)
port = 5432 # (change requires restart)
max_connections = 500 # (change requires restart)
# 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 # (change requires restart)
unix_socket_directory = '/var/run/postgresql' # (change requires restart)
#unix_socket_group = '' # (change requires restart)
#unix_socket_permissions = 0777 # octal
# (change requires restart)
#bonjour_name = '' # defaults to the computer name
# (change requires restart)

# - Security & Authentication -

authentication_timeout = 60s # 1s-600s
ssl = off # (change requires restart)
password_encryption = off
db_user_namespace = off

# Kerberos
#krb_server_keyfile = '' # (change requires restart)
#krb_srvname = 'postgres' # (change requires restart)
#krb_server_hostname = '' # empty string matches any keytab entry
# (change requires restart)
#krb_caseins_users = off # (change requires restart)

# - 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 = 512MB # min 128kB or max_connections*16kB
# (change requires restart)
temp_buffers = 56MB # min 800kB
#max_prepared_transactions = 5 # can be 0 or more
# (change requires restart)
# Note: increasing max_prepared_transactions costs ~600 bytes of shared
memory
# per transaction slot, plus lock space (see max_locks_per_transaction).
work_mem = 512MB # min 64kB
maintenance_work_mem = 1024MB # min 1MB
max_stack_depth = 6MB # min 100kB

# - Free Space Map -

max_fsm_pages = 204800 # min max_fsm_relations*16, 6 bytes each
# (change requires restart)
#max_fsm_relations = 1000 # min 100, ~70 bytes each
# (change requires restart)

# - Kernel Resource Usage -

max_files_per_process = 2000 # min 25
# (change requires restart)
#shared_preload_libraries = '' # (change requires restart)

# - Cost-Based Vacuum Delay -

#vacuum_cost_delay = 0 # 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 = 200ms # 10-10000ms 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 = 64kB # min 32kB
# (change requires restart)
#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 = 60s # range 30s-1h
checkpoint_warning = 30s # 0 is off

# - Archiving -

#archive_command = '' # command to use to archive a logfile segment
#archive_timeout = 0 # force a logfile segment switch after this
# many seconds; 0 is off

#---------------------------------------------------------------------------
# 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 = off
#enable_tidscan = on

# - Planner Cost Constants -

seq_page_cost = 2.0 # measured on an arbitrary scale
random_page_cost = 4.0 # same scale as above
cpu_tuple_cost = 0.5 # same scale as above
cpu_index_tuple_cost = 0.1 # same scale as above
cpu_operator_cost = 0.1 # same scale as above
effective_cache_size = 128MB

# - 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 = 'stderr' # Valid values are combinations of
# stderr, syslog and eventlog,
# depending on platform.

# This is used when logging to stderr:
#redirect_stderr = off # Enable capturing of stderr into log
# files
# (change requires restart)

# 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.
# Can include strftime() escapes
#log_truncate_on_rotation = off # 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 = 1d # Automatic rotation of logfiles will
# happen after that time. 0 to
# disable.
#log_rotation_size = 10MB # Automatic rotation of logfiles will
# happen after that much 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 = error # Values in order of increasing severity:
# debug5
# debug4
# debug3
# debug2
# debug1
# info
# notice
# warning
# error
# fatal
# panic (effectively off)

#log_min_duration_statement = -1 # -1 is disabled, 0 logs all statements
# and their durations.

#silent_mode = off # DO NOT USE without syslog or
# redirect_stderr
# (change requires restart)

# - 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 = '%t %d %h %u' # 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, ddl, mod, all
#log_hostname = off

#---------------------------------------------------------------------------
# RUNTIME STATISTICS
#---------------------------------------------------------------------------

# - Query/Index Statistics Collector -

#stats_command_string = on
#update_process_title = on

#stats_start_collector = on # needed for block or row stats
# (change requires restart)
#stats_block_level = off
stats_row_level = on
#stats_reset_on_server_start = off # (change requires restart)

# - Statistics Monitoring -

#log_parser_stats = off
#log_planner_stats = off
#log_executor_stats = off
#log_statement_stats = off

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

autovacuum = off # enable autovacuum subprocess?
# 'on' requires stats_start_collector
# and stats_row_level to also be on
#autovacuum_naptime = 1min # time between autovacuum runs
#autovacuum_vacuum_threshold = 500 # min # of tuple updates before
# vacuum
#autovacuum_analyze_threshold = 250 # min # of tuple updates before
# analyze
#autovacuum_vacuum_scale_factor = 0.2 # fraction of rel size before
# vacuum
#autovacuum_analyze_scale_factor = 0.1 # fraction of rel size before
# analyze
#autovacuum_freeze_max_age = 200000000 # maximum XID age before forced
vacuum
# (change requires restart)
#autovacuum_vacuum_cost_delay = -1 # default vacuum cost delay for
# autovacuum, -1 means use
# vacuum_cost_delay
#autovacuum_vacuum_cost_limit = -1 # default vacuum cost limit for
# autovacuum, -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 = off
#default_transaction_isolation = 'read committed'
#default_transaction_read_only = off
#statement_timeout = 0 # 0 is disabled
#vacuum_freeze_min_age = 100000000

# - Locale and Formatting -

datestyle = 'sql, dmy'
#timezone = unknown # actually, defaults to TZ
# environment setting
#timezone_abbreviations = 'Default' # select the set of available
timezone
# abbreviations. Currently, there are
# Default
# Australia
# India
# However you can also create your own
# file in share/timezonesets/.
#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' # locale for system error message
# strings
lc_monetary = 'pt_BR' # locale for monetary formatting
lc_numeric = 'pt_BR' # locale for number formatting
lc_time = 'pt_BR' # locale for time formatting

# - Other Defaults -

#explain_pretty_print = on
#dynamic_library_path = '$libdir'
#local_preload_libraries = ''

#---------------------------------------------------------------------------
# LOCK MANAGEMENT
#---------------------------------------------------------------------------

deadlock_timeout = 10s
max_locks_per_transaction = 64 # min 10
# (change requires restart)
# Note: each lock table slot uses ~270 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
#array_nulls = on
#backslash_quote = safe_encoding # on, off, or safe_encoding
#default_with_oids = off
#escape_string_warning = on
#standard_conforming_strings = 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

=====================================================================

Atentamente,

Antonio Salas Mena