# \d credit
                                     Table "public.credit"
  Column   |            Type             |                      Modifiers                      
-----------+-----------------------------+-----------------------------------------------------
 id        | integer                     | not null default nextval('credit_id_seq'::regclass)
 dated     | timestamp without time zone | 
 debit_id  | integer                     | 
 credit_id | integer                     | 
 total     | integer                     | 
 note      | character varying(255)      | 
 advert_id | integer                     | 
Indexes:
    "credit_pkey" PRIMARY KEY, btree (id)
    "credit_creditindex" btree (credit_id)
    "credit_datedindex" btree (dated)
    "credit_debitindex" btree (debit_id)
Foreign-key constraints:
    "advert_id_exists" FOREIGN KEY (advert_id) REFERENCES advert(id)
    "credit_id_exists" FOREIGN KEY (credit_id) REFERENCES tg_user(id)
    "debit_id_exists" FOREIGN KEY (debit_id) REFERENCES tg_user(id)


=> select count(*) from credit;
  count  
---------
 6750421

=> select attname,n_distinct from pg_stats where tablename='credit';~                                                                               
  attname  | n_distinct 
-----------+------------
 id        |         -1
 dated     |     243344
 debit_id  |        665
 advert_id |         -1
 credit_id |       3689
 total     |        155
 note      |       1986
(7 rows)


# explain SELECT credit.id, credit.dated, credit.debit_id, credit.credit_id, credit.total, credit.note, credit.advert_id FROM credit WHERE (((credit.credit_id) = (5624)) OR ((credit.debit_id) = (5624))) ORDER BY dated DESC LIMIT 30;
                                               QUERY PLAN                                               
--------------------------------------------------------------------------------------------------------
 Limit  (cost=0.00..1085.11 rows=30 width=50)
   ->  Index Scan Backward using credit_datedindex on credit  (cost=0.00..197996.92 rows=5474 width=50)
         Filter: ((credit_id = 5624) OR (debit_id = 5624))



# explain select credit.id, credit.dated, credit.debit_id, credit.credit_id, credit.total, credit.note, credit.advert_id FROM credit WHERE (((credit.credit_id) = (5624)) OR ((credit.debit_id) = (5624))) LIMIT 30;
                                           QUERY PLAN                                            
-------------------------------------------------------------------------------------------------
 Limit  (cost=36.17..128.40 rows=30 width=50)
   ->  Bitmap Heap Scan on credit  (cost=36.17..16868.45 rows=5475 width=50)
         Recheck Cond: ((credit_id = 5624) OR (debit_id = 5624))
         ->  BitmapOr  (cost=36.17..36.17 rows=5476 width=0)
               ->  Bitmap Index Scan on credit_creditindex  (cost=0.00..21.02 rows=3149 width=0)
                     Index Cond: (credit_id = 5624)
               ->  Bitmap Index Scan on credit_debitindex  (cost=0.00..15.14 rows=2327 width=0)
                     Index Cond: (debit_id = 5624)
(8 rows)



### ID changed to maintain original conditions (no matching rows)

=> explain analyze SELECT credit.id, credit.dated, credit.debit_id, credit.credit_id, credit.total, credit.note, credit.advert_id FROM credit WHERE (((credit.credit_id) = (9999)) OR ((credit.debit_id) = (9999))) ORDER BY dated DESC LIMIT 30;
                                                                         QUERY PLAN                                                                         
------------------------------------------------------------------------------------------------------------------------------------------------------------
 Limit  (cost=0.00..3418.00 rows=30 width=50) (actual time=211316.283..211316.283 rows=0 loops=1)
   ->  Index Scan Backward using credit_datedindex on credit  (cost=0.00..199611.42 rows=1752 width=50) (actual time=211316.278..211316.278 rows=0 loops=1)
         Filter: ((credit_id = 9999) OR (debit_id = 9999))
 Total runtime: 211316.326 ms


=> set enable_indexscan=false;
SET
=> explain analyze SELECT credit.id, credit.dated, credit.debit_id, credit.credit_id, credit.total, credit.note, credit.advert_id FROM credit WHERE (((credit.credit_id) = (9999)) OR ((credit.debit_id) = (9999))) ORDER BY dated DESC LIMIT 30;
                                                                   QUERY PLAN                                                                   
------------------------------------------------------------------------------------------------------------------------------------------------
 Limit  (cost=6241.12..6241.19 rows=30 width=50) (actual time=0.175..0.175 rows=0 loops=1)
   ->  Sort  (cost=6241.12..6245.50 rows=1752 width=50) (actual time=0.172..0.172 rows=0 loops=1)
         Sort Key: dated
         ->  Bitmap Heap Scan on credit  (cost=13.13..6146.73 rows=1752 width=50) (actual time=0.095..0.095 rows=0 loops=1)
               Recheck Cond: ((credit_id = 9999) OR (debit_id = 9999))
               ->  BitmapOr  (cost=13.13..13.13 rows=1752 width=0) (actual time=0.093..0.093 rows=0 loops=1)
                     ->  Bitmap Index Scan on credit_creditindex  (cost=0.00..9.91 rows=1404 width=0) (actual time=0.047..0.047 rows=0 loops=1)
                           Index Cond: (credit_id = 9999)
                     ->  Bitmap Index Scan on credit_debitindex  (cost=0.00..3.22 rows=348 width=0) (actual time=0.044..0.044 rows=0 loops=1)
                           Index Cond: (debit_id = 9999)
 Total runtime: 0.216 ms
(11 rows)


---- System configuration ----

4xDual core Xeon 2ghz

Mem:   2070736k total,  2017944k used,    52792k free,     4268k buffers
Swap:  2040244k total,       64k used,  2040180k free,  1817620k cached


=> select version();
                                                 version                                                 
---------------------------------------------------------------------------------------------------------
 PostgreSQL 8.1.11 on i686-redhat-linux-gnu, compiled by GCC gcc (GCC) 4.1.2 20070626 (Red Hat 4.1.2-14)


#---------------------------------------------------------------------------
# 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 = 200
# 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 = 19200                  # 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_relations = 1000               # 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_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 = 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


#---------------------------------------------------------------------------
# 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 = 65535            # typically 8KB each
#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 = '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 = on
stats_command_string = on
#stats_block_level = off
#stats_row_level = off
#stats_reset_on_server_start = off


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

#autovacuum = off                       # 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, 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
                                        # encoding

# These settings are initialized by initdb -- they might be changed
lc_messages = 'en_US.UTF-8'                     # locale for system error message 
                                        # strings
lc_monetary = 'en_US.UTF-8'                     # locale for monetary formatting
lc_numeric = 'en_US.UTF-8'                      # locale for number formatting
lc_time = 'en_US.UTF-8'                         # 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



##### Output of show all;

add_missing_from                | off            | Automatically adds missing table references to FROM clauses.
 archive_command                 | unset          | WAL archiving command.
 australian_timezones            | off            | Interprets ACST, CST, EST, and SAT as Australian time zones.
 authentication_timeout          | 60             | Sets the maximum time in seconds to complete client authentication.
 autovacuum                      | off            | Starts the autovacuum subprocess.
 autovacuum_analyze_scale_factor | 0.2            | Number of tuple inserts, updates or deletes prior to analyze as a fraction of reltuples.
 autovacuum_analyze_threshold    | 500            | Minimum number of tuple inserts, updates or deletes prior to analyze.
 autovacuum_naptime              | 60             | Time to sleep between autovacuum runs, in seconds.
 autovacuum_vacuum_cost_delay    | -1             | Vacuum cost delay in milliseconds, for autovacuum.
 autovacuum_vacuum_cost_limit    | -1             | Vacuum cost amount available before napping, for autovacuum.
 autovacuum_vacuum_scale_factor  | 0.4            | Number of tuple updates or deletes prior to vacuum as a fraction of reltuples.
 autovacuum_vacuum_threshold     | 1000           | Minimum number of tuple updates or deletes prior to vacuum.
 backslash_quote                 | safe_encoding  | Sets whether "\'" is allowed in string literals.
 bgwriter_all_maxpages           | 5              | Background writer maximum number of all pages to flush per round
 bgwriter_all_percent            | 0.333          | Background writer percentage of all buffers to flush per round
 bgwriter_delay                  | 200            | Background writer sleep time between rounds in milliseconds
 bgwriter_lru_maxpages           | 5              | Background writer maximum number of LRU pages to flush per round
 bgwriter_lru_percent            | 1              | Background writer percentage of LRU buffers to flush per round
 block_size                      | 8192           | Shows size of a disk block
 bonjour_name                    | unset          | Sets the Bonjour broadcast service name.
 check_function_bodies           | on             | Check function bodies during CREATE FUNCTION.
 checkpoint_segments             | 3              | Sets the maximum distance in log segments between automatic WAL checkpoints.
 checkpoint_timeout              | 300            | Sets the maximum time in seconds between automatic WAL checkpoints.
 checkpoint_warning              | 30             | Logs if filling of checkpoint segments happens more frequently than this (in seconds).
 client_encoding                 | UTF8           | Sets the client's character set encoding.
 client_min_messages             | notice         | Sets the message levels that are sent to the client.
 commit_delay                    | 0              | Sets the delay in microseconds between transaction commit and flushing WAL to disk.
 commit_siblings                 | 5              | Sets the minimum concurrent open transactions before performing commit_delay.
 constraint_exclusion            | off            | Enables the planner to use constraints to optimize queries.
 cpu_index_tuple_cost            | 0.001          | Sets the planner's estimate of processing cost for each index tuple (row) during index scan.
 cpu_operator_cost               | 0.0025         | Sets the planner's estimate of processing cost of each operator in WHERE.
 cpu_tuple_cost                  | 0.01           | Sets the planner's estimate of the cost of processing each tuple (row).
 custom_variable_classes         | unset          | Sets the list of known custom variable classes.
 DateStyle                       | ISO, MDY       | Sets the display format for date and time values.
 db_user_namespace               | off            | Enables per-database user names.
 deadlock_timeout                | 1000           | The time in milliseconds to wait on lock before checking for deadlock.
 debug_pretty_print              | off            | Indents parse and plan tree displays.
 debug_print_parse               | off            | Prints the parse tree to the server log.
 debug_print_plan                | off            | Prints the execution plan to server log.
 debug_print_rewritten           | off            | Prints the parse tree after rewriting to server log.
 default_statistics_target       | 100            | Sets the default statistics target.
default_tablespace              | unset          | Sets the default tablespace to create tables and indexes in.
 default_transaction_isolation   | read committed | Sets the transaction isolation level of each new transaction.
 default_transaction_read_only   | off            | Sets the default read-only status of new transactions.
 default_with_oids               | off            | Create new tables with OIDs by default.
 effective_cache_size            | 65535          | Sets the planner's assumption about size of the disk cache.
 enable_bitmapscan               | on             | Enables the planner's use of bitmap-scan plans.
 enable_hashagg                  | on             | Enables the planner's use of hashed aggregation plans.
 enable_hashjoin                 | on             | Enables the planner's use of hash join plans.
 enable_indexscan                | on             | Enables the planner's use of index-scan plans.
 enable_mergejoin                | on             | Enables the planner's use of merge join plans.
 enable_nestloop                 | on             | Enables the planner's use of nested-loop join plans.
 enable_seqscan                  | on             | Enables the planner's use of sequential-scan plans.
 enable_sort                     | on             | Enables the planner's use of explicit sort steps.
 enable_tidscan                  | on             | Enables the planner's use of TID scan plans.
 escape_string_warning           | off            | Warn about backslash escapes in ordinary string literals.
 explain_pretty_print            | on             | Uses the indented output format for EXPLAIN VERBOSE.
 extra_float_digits              | 0              | Sets the number of digits displayed for floating-point values.
 from_collapse_limit             | 8              | Sets the FROM-list size beyond which subqueries are not collapsed.
 fsync                           | on             | Forces synchronization of updates to disk.
 full_page_writes                | on             | Writes full pages to WAL when first modified after a checkpoint.
 geqo                            | on             | Enables genetic query optimization.
 geqo_effort                     | 5              | GEQO: effort is used to set the default for other GEQO parameters.
 geqo_generations                | 0              | GEQO: number of iterations of the algorithm.
 geqo_pool_size                  | 0              | GEQO: number of individuals in the population.
 geqo_selection_bias             | 2              | GEQO: selective pressure within the population.
 geqo_threshold                  | 12             | Sets the threshold of FROM items beyond which GEQO is used.
 integer_datetimes               | off            | Datetimes are integer based.
 join_collapse_limit             | 8              | Sets the FROM-list size beyond which JOIN constructs are not flattened.
 krb_caseins_users               | off            | Sets whether Kerberos user names should be treated as case-insensitive.
 krb_server_hostname             | unset          | Sets the hostname of the Kerberos server.
 krb_srvname                     | postgres       | Sets the name of the Kerberos service.
 lc_collate                      | en_US.UTF-8    | Shows the collation order locale.
 lc_ctype                        | en_US.UTF-8    | Shows the character classification and case conversion locale.
 lc_messages                     | en_US.UTF-8    | Sets the language in which messages are displayed.
 lc_monetary                     | en_US.UTF-8    | Sets the locale for formatting monetary amounts.
 lc_numeric                      | en_US.UTF-8    | Sets the locale for formatting numbers.
 lc_time                         | en_US.UTF-8    | Sets the locale for formatting date and time values.
 listen_addresses                | *              | Sets the host name or IP address(es) to listen to.
 log_connections                 | off            | Logs each successful connection.
 log_destination                 | stderr         | Sets the destination for server log output.
 log_disconnections              | off            | Logs end of a session, including duration.
 log_duration                    | off            | Logs the duration of each completed SQL statement.
 log_error_verbosity             | default        | Sets the verbosity of logged messages.
 log_executor_stats              | off            | Writes executor performance statistics to the server log.
 log_hostname                    | off            | Logs the host name in the connection logs.
 log_line_prefix                 | unset          | Controls information prefixed to each log line
 log_min_duration_statement      | -1             | Sets the minimum execution time in milliseconds above which statements will be logged.
 log_min_error_statement         | panic          | Causes all statements generating error at or above this level to be logged.
 log_min_messages                | notice         | Sets the message levels that are logged.
 log_parser_stats                | off            | Writes parser performance statistics to the server log.
 log_planner_stats               | off            | Writes planner performance statistics to the server log.
 log_rotation_age                | 1440           | Automatic log file rotation will occur after N minutes
 log_rotation_size               | 0              | Automatic log file rotation will occur after N kilobytes
 log_statement                   | none           | Sets the type of statements logged.
 log_statement_stats             | off            | Writes cumulative performance statistics to the server log.
 log_truncate_on_rotation        | on             | Truncate existing log files of same name during log rotation.
 maintenance_work_mem            | 16384          | Sets the maximum memory to be used for maintenance operations.
 max_connections                 | 200            | Sets the maximum number of concurrent connections.
 max_files_per_process           | 1000           | Sets the maximum number of simultaneously open files for each server process.
 max_fsm_pages                   | 20000          | Sets the maximum number of disk pages for which free space is tracked.
 max_fsm_relations               | 1000           | Sets the maximum number of tables and indexes for which free space is tracked.
 max_function_args               | 100            | Shows the maximum number of function arguments.
 max_identifier_length           | 63             | Shows the maximum identifier length
 max_index_keys                  | 32             | Shows the maximum number of index keys.
 max_locks_per_transaction       | 64             | Sets the maximum number of locks per transaction.
 max_prepared_transactions       | 5              | Sets the maximum number of simultaneously prepared transactions.
 max_stack_depth                 | 2048           | Sets the maximum stack depth, in kilobytes.
 password_encryption             | on             | Encrypt passwords.
 port                            | 5432           | Sets the TCP port the server listens on.
 pre_auth_delay                  | 0              | no description available
 random_page_cost                | 4              | Sets the planner's estimate of the cost of a nonsequentially fetched disk page.
 redirect_stderr                 | on             | Start a subprocess to capture stderr output into log files.
 regex_flavor                    | advanced       | Sets the regular expression "flavor".
 search_path                     | $user,public   | Sets the schema search order for names that are not schema-qualified.
 server_encoding                 | UTF8           | Sets the server (database) character set encoding.
 server_version                  | 8.1.11         | Shows the server version.
 shared_buffers                  | 19200          | Sets the number of shared memory buffers used by the server.
 silent_mode                     | off            | Runs the server silently.
 sql_inheritance                 | on             | Causes subtables to be included by default in various commands.
 ssl                             | off            | Enables SSL connections.
 standard_conforming_strings     | off            | '...' strings treat backslashes literally.
 statement_timeout               | 0              | Sets the maximum allowed duration (in milliseconds) of any statement.
 stats_block_level               | off            | Collects block-level statistics on database activity.
 stats_command_string            | on             | Collects statistics about executing commands.
 stats_reset_on_server_start     | off            | Zeroes collected statistics on server restart.
 stats_row_level                 | off            | Collects row-level statistics on database activity.
 random_page_cost                | 4              | Sets the planner's estimate of the cost of a nonsequentially fetched disk page.
 redirect_stderr                 | on             | Start a subprocess to capture stderr output into log files.
 regex_flavor                    | advanced       | Sets the regular expression "flavor".
 search_path                     | $user,public   | Sets the schema search order for names that are not schema-qualified.
 server_encoding                 | UTF8           | Sets the server (database) character set encoding.
 server_version                  | 8.1.11         | Shows the server version.
 shared_buffers                  | 19200          | Sets the number of shared memory buffers used by the server.
 silent_mode                     | off            | Runs the server silently.
 sql_inheritance                 | on             | Causes subtables to be included by default in various commands.
 ssl                             | off            | Enables SSL connections.
 standard_conforming_strings     | off            | '...' strings treat backslashes literally.
 statement_timeout               | 0              | Sets the maximum allowed duration (in milliseconds) of any statement.
 stats_block_level               | off            | Collects block-level statistics on database activity.
 stats_command_string            | on             | Collects statistics about executing commands.
 stats_reset_on_server_start     | off            | Zeroes collected statistics on server restart.
 stats_row_level                 | off            | Collects row-level statistics on database activity.
 stats_start_collector           | on             | Starts the server statistics-collection subprocess.
 superuser_reserved_connections  | 2              | Sets the number of connection slots reserved for superusers.
 syslog_facility                 | LOCAL0         | Sets the syslog "facility" to be used when syslog enabled.
 syslog_ident                    | postgres       | Sets the program name used to identify PostgreSQL messages in syslog.
 tcp_keepalives_count            | 9              | Maximum number of TCP keepalive retransmits.
 tcp_keepalives_idle             | 7200           | Seconds between issuing TCP keepalives.
 tcp_keepalives_interval         | 75             | Seconds between TCP keepalive retransmits.
 temp_buffers                    | 1000           | Sets the maximum number of temporary buffers used by each session.
 TimeZone                        | US/Eastern     | Sets the time zone for displaying and interpreting time stamps.
 trace_notify                    | off            | Generates debugging output for LISTEN and NOTIFY.
 trace_sort                      | off            | Emit information about resource usage in sorting.
 transaction_isolation           | read committed | Sets the current transaction's isolation level.
 transaction_read_only           | off            | Sets the current transaction's read-only status.
 transform_null_equals           | off            | Treats "expr=NULL" as "expr IS NULL".
 unix_socket_group               | unset          | Sets the owning group of the Unix-domain socket.
 unix_socket_permissions         | 511            | Sets the access permissions of the Unix-domain socket.
 vacuum_cost_delay               | 0              | Vacuum cost delay in milliseconds.
 vacuum_cost_limit               | 200            | Vacuum cost amount available before napping.
 vacuum_cost_page_dirty          | 20             | Vacuum cost for a page dirtied by vacuum.
 vacuum_cost_page_hit            | 1              | Vacuum cost for a page found in the buffer cache.
 vacuum_cost_page_miss           | 10             | Vacuum cost for a page not found in the buffer cache.
 wal_buffers                     | 8              | Sets the number of disk-page buffers in shared memory for WAL.
 wal_sync_method                 | fdatasync      | Selects the method used for forcing WAL updates out to disk.
 work_mem                        | 1024           | Sets the maximum memory to be used for query workspaces.
 zero_damaged_pages              | off            | Continues processing past damaged page headers.