Re: Almost infinite query -> Different Query Plan when changing where clause value - Mailing list pgsql-performance

Thanks kevin for your answer. Here is some additionnal informations
attached as files.


regards.
Lionel

Kevin Grittner a écrit :
> lionel duboeuf <lionel.duboeuf@boozter.com> wrote:
>
>
>> Some informations:
>> The following problem has been detected on
>>    Postgresql 8.3 and 8.4. on System linux or windows
>>    Default AutoVacuum daemon working
>>    One pg_dump every day
>> This happens sometimes and i don't see what can be the cause.
>> A manual Vacuum Analyse repair that problem.
>>
>
> It's good to know that the issue has been observed in more than one
> release or on more than one platform, but it's also useful to get a
> bit more information about one particular occurrence.  Please read
> this:
>
> http://wiki.postgresql.org/wiki/SlowQueryQuestions
>
> In particular, knowing such things as your postgresql.conf settings,
> the disk configuration, how much RAM the machine has, etc. can allow
> us to provide more useful advice.
>
> Please run these as EXPLAIN ANALYZE (or at least whatever you can
> get to finish that way) instead of just EXPLAIN.  If you can let the
> slow one run through EXPLAIN ANALYZE overnight or on a test machine
> so that it can complete, it will give us a lot more with which to
> work.  Please attach wide output (like that from EXPLAIN) as a text
> attachment, to prevent wrapping which makes it hard to read.
>
> -Kevin
>

processor    : 0
vendor_id    : GenuineIntel
cpu family    : 6
model        : 15
model name    : Intel(R) Core(TM)2 Duo CPU     T7500  @ 2.20GHz
stepping    : 11
cpu MHz        : 2201.000
cache size    : 4096 KB
physical id    : 0
siblings    : 2
core id        : 0
cpu cores    : 2
apicid        : 0
initial apicid    : 0
fdiv_bug    : no
hlt_bug        : no
f00f_bug    : no
coma_bug    : no
fpu        : yes
fpu_exception    : yes
cpuid level    : 10
wp        : yes
flags        : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2
ssht tm pbe nx lm constant_tsc arch_perfmon pebs bts pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm lahf_lm
idatpr_shadow vnmi flexpriority 
bogomips    : 4389.59
clflush size    : 64
power management:

processor    : 1
vendor_id    : GenuineIntel
cpu family    : 6
model        : 15
model name    : Intel(R) Core(TM)2 Duo CPU     T7500  @ 2.20GHz
stepping    : 11
cpu MHz        : 2201.000
cache size    : 4096 KB
physical id    : 0
siblings    : 2
core id        : 1
cpu cores    : 2
apicid        : 1
initial apicid    : 1
fdiv_bug    : no
hlt_bug        : no
f00f_bug    : no
coma_bug    : no
fpu        : yes
fpu_exception    : yes
cpuid level    : 10
wp        : yes
flags        : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2
ssht tm pbe nx lm constant_tsc arch_perfmon pebs bts pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm lahf_lm
idatpr_shadow vnmi flexpriority 
bogomips    : 4388.96
clflush size    : 64
power management:

QUERY PLAN
Nested Loop  (cost=58.71..1512.50 rows=1 width=16) (actual time=1.849..535681.136 rows=14 loops=1)
  ->  Nested Loop  (cost=58.71..1506.60 rows=1 width=20) (actual time=1.839..535680.377 rows=14 loops=1)
        Join Filter: (link0_.element_source = blocks9_.element_seqnum)
        ->  Nested Loop  (cost=58.71..1498.29 rows=1 width=32) (actual time=1.819..535337.910 rows=6534 loops=1)
              ->  Nested Loop  (cost=58.71..1497.14 rows=1 width=28) (actual time=1.811..535246.825 rows=6534 loops=1)
                    ->  Nested Loop  (cost=58.71..1488.83 rows=1 width=36) (actual time=1.800..535160.718 rows=6534
loops=1)
                          ->  Nested Loop  (cost=58.71..1484.40 rows=1 width=28) (actual time=1.772..535042.549
rows=6534loops=1) 
                                ->  Nested Loop  (cost=13.20..1434.87 rows=1 width=16) (actual time=1.398..8327.567
rows=122850loops=1) 
                                      ->  Nested Loop  (cost=13.20..1428.97 rows=1 width=20) (actual
time=1.387..1911.520rows=122850 loops=1) 
                                            ->  Nested Loop  (cost=13.20..1427.83 rows=1 width=24) (actual
time=1.374..517.662rows=122850 loops=1) 
                                                  ->  Nested Loop  (cost=0.00..16.63 rows=1 width=16) (actual
time=0.085..0.409rows=15 loops=1) 
                                                        ->  Index Scan using fki_element_block_block on element_block
blocks7_ (cost=0.00..8.30 rows=1 width=8) (actual time=0.045..0.082 rows=15 loops=1) 
                                                              Index Cond: (block_seqnum = 5)
                                                        ->  Index Scan using pk_user_element on user_element users3_
(cost=0.00..8.33rows=1 width=8) (actual time=0.012..0.015 rows=1 loops=15) 
                                                              Index Cond: ((users3_.user_seqnum = 10) AND
(users3_.element_seqnum= blocks7_.element_seqnum)) 
                                                  ->  Bitmap Heap Scan on user_element users5_  (cost=13.20..1404.85
rows=634width=8) (actual time=1.091..12.478 rows=8190 loops=15) 
                                                        Recheck Cond: (users5_.user_seqnum = 10)
                                                        ->  Bitmap Index Scan on fki_user_element_user
(cost=0.00..13.05rows=634 width=0) (actual time=1.062..1.062 rows=8194 loops=15) 
                                                              Index Cond: (users5_.user_seqnum = 10)
                                            ->  Seq Scan on block block8_  (cost=0.00..1.14 rows=1 width=4) (actual
time=0.004..0.005rows=1 loops=122850) 
                                                  Filter: (block8_.block_seqnum = 5)
                                      ->  Seq Scan on "user" user4_  (cost=0.00..5.89 rows=1 width=4) (actual
time=0.005..0.047rows=1 loops=122850) 
                                            Filter: (user4_.user_seqnum = 10)
                                ->  Bitmap Heap Scan on link link0_  (cost=45.50..49.51 rows=1 width=12) (actual
time=4.283..4.283rows=0 loops=122850) 
                                      Recheck Cond: ((link0_.element_source = users5_.element_seqnum) AND
(link0_.element_target= users3_.element_seqnum)) 
                                      Filter: (link0_.link_sup_date IS NULL)
                                      ->  BitmapAnd  (cost=45.50..45.50 rows=1 width=0) (actual time=4.280..4.280
rows=0loops=122850) 
                                            ->  Bitmap Index Scan on element_source_fk  (cost=0.00..4.61 rows=21
width=0)(actual time=0.007..0.007 rows=6 loops=122850) 
                                                  Index Cond: (link0_.element_source = users5_.element_seqnum)
                                            ->  Bitmap Index Scan on element_target_fk  (cost=0.00..40.12 rows=2089
width=0)(actual time=4.719..4.719 rows=33814 loops=110880) 
                                                  Index Cond: (link0_.element_target = users3_.element_seqnum)
                          ->  Index Scan using pk_element on element element2_  (cost=0.00..4.41 rows=1 width=8)
(actualtime=0.009..0.011 rows=1 loops=6534) 
                                Index Cond: (element2_.element_seqnum = link0_.element_source)
                    ->  Index Scan using pk_element on element element1_  (cost=0.00..8.31 rows=1 width=4) (actual
time=0.006..0.007rows=1 loops=6534) 
                          Index Cond: (element1_.element_seqnum = link0_.element_target)
              ->  Seq Scan on block block10_  (cost=0.00..1.14 rows=1 width=4) (actual time=0.005..0.007 rows=1
loops=6534)
                    Filter: (block10_.block_seqnum = 5)
        ->  Index Scan using fki_element_block_block on element_block blocks9_  (cost=0.00..8.30 rows=1 width=8)
(actualtime=0.007..0.030 rows=15 loops=6534) 
              Index Cond: (blocks9_.block_seqnum = 5)
  ->  Seq Scan on "user" user6_  (cost=0.00..5.89 rows=1 width=4) (actual time=0.006..0.048 rows=1 loops=14)
        Filter: (user6_.user_seqnum = 10)
Total runtime: 535681.414 ms
MemTotal:        3087448 kB
MemFree:         2355500 kB
Buffers:           22212 kB
Cached:           396520 kB
SwapCached:            0 kB
Active:           387472 kB
Inactive:         289388 kB
Active(anon):     313808 kB
Inactive(anon):        0 kB
Active(file):      73664 kB
Inactive(file):   289388 kB
Unevictable:           0 kB
Mlocked:               0 kB
HighTotal:       2226696 kB
HighFree:        1560912 kB
LowTotal:         860752 kB
LowFree:          794588 kB
SwapTotal:             0 kB
SwapFree:              0 kB
Dirty:              6216 kB
Writeback:             0 kB
AnonPages:        258144 kB
Mapped:           127688 kB
Slab:              28196 kB
SReclaimable:      14624 kB
SUnreclaim:        13572 kB
PageTables:         5272 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:     1543724 kB
Committed_AS:     913152 kB
VmallocTotal:     122880 kB
VmallocUsed:       11192 kB
VmallocChunk:      88472 kB
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       4096 kB
DirectMap4k:       16376 kB
DirectMap4M:      892928 kB
# -----------------------------
# PostgreSQL configuration file
# -----------------------------
#
# This file consists of lines of the form:
#
#   name = value
#
# (The "=" is optional.)  Whitespace may be used.  Comments are introduced with
# "#" anywhere on a line.  The complete list of parameter names and allowed
# values can be found in the PostgreSQL documentation.
#
# The commented-out settings shown in this file represent the default values.
# Re-commenting a setting is NOT sufficient to revert it to the default value;
# you need to reload the server.
#
# This file is read on server startup and when the server receives a SIGHUP
# signal.  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
# parameters, which are marked below, require a server shutdown and restart to
# take effect.
#
# Any parameter can also be given as a command-line option to the server, e.g.,
# "postgres -c log_connections=on".  Some paramters can be changed at run time
# with the "SET" SQL command.
#
# 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
# option or PGDATA environment variable, represented here as ConfigDir.

data_directory = '/var/lib/postgresql/8.3/main'        # use data in another directory
                    # (change requires restart)
hba_file = '/etc/postgresql/8.3/main/pg_hba.conf'    # host-based authentication file
                    # (change requires restart)
ident_file = '/etc/postgresql/8.3/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/8.3-main.pid'        # write an extra PID file
                    # (change requires restart)


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

# - Connection Settings -

#listen_addresses = 'localhost'        # 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 = 100            # (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 = 3    # (change requires restart)
unix_socket_directory = '/var/run/postgresql'        # (change requires restart)
#unix_socket_group = ''            # (change requires restart)
#unix_socket_permissions = 0777        # begin with 0 to use octal notation
                    # (change requires restart)
#bonjour_name = ''            # defaults to the computer name
                    # (change requires restart)

# - Security and Authentication -

#authentication_timeout = 1min        # 1s-600s
ssl = true                # (change requires restart)
#ssl_ciphers = 'ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH'    # allowed SSL ciphers
                    # (change requires restart)
#password_encryption = on
#db_user_namespace = off

# Kerberos and GSSAPI
#krb_server_keyfile = ''        # (change requires restart)
#krb_srvname = 'postgres'        # (change requires restart, Kerberos only)
#krb_server_hostname = ''        # empty string matches any keytab entry
                    # (change requires restart, Kerberos only)
#krb_caseins_users = off        # (change requires restart)
#krb_realm = ''                   # (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 = 24MB            # min 128kB or max_connections*16kB
                    # (change requires restart)
#temp_buffers = 8MB            # 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 = 1MB                # min 64kB
#maintenance_work_mem = 16MB        # min 1MB
#max_stack_depth = 2MB            # min 100kB

# - Free Space Map -

max_fsm_pages = 153600            # 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 = 1000        # 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        # 1-10000 credits

# - Background Writer -

#bgwriter_delay = 200ms            # 10-10000ms between rounds
#bgwriter_lru_maxpages = 100        # 0-1000 max buffers written/round
#bgwriter_lru_multiplier = 2.0        # 0-10.0 multipler on buffers scanned/round


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

# - Settings -

#fsync = on                # turns forced synchronization on or off
#synchronous_commit = on        # immediate fsync at commit
#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)
#wal_writer_delay = 200ms        # 1-10000 milliseconds

#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 = 5min        # range 30s-1h
#checkpoint_completion_target = 0.5    # checkpoint target duration, 0.0 - 1.0
#checkpoint_warning = 30s        # 0 is off

# - Archiving -

#archive_mode = off        # allows archiving to be done
                # (change requires restart)
#archive_command = ''        # command to use to archive a logfile segment
#archive_timeout = 0        # force a logfile segment switch after this
                # time; 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 = on
#enable_tidscan = on

# - Planner Cost Constants -

#seq_page_cost = 1.0            # measured on an arbitrary scale
#random_page_cost = 4.0            # same scale as above
#cpu_tuple_cost = 0.01            # same scale as above
#cpu_index_tuple_cost = 0.005        # same scale as above
#cpu_operator_cost = 0.0025        # 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
                    # JOIN clauses


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

# - Where to Log -

#log_destination = 'stderr'        # Valid values are combinations of
                    # stderr, csvlog, syslog and eventlog,
                    # depending on platform.  csvlog
                    # requires logging_collector to be on.

# This is used when logging to stderr:
logging_collector = on        # Enable capturing of stderr and csvlog
                    # into log files. Required to be on for
                    # csvlogs.
                    # (change requires restart)

# These are only used if logging_collector 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, an 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 decreasing detail:
                     #   debug5
                    #   debug4
                    #   debug3
                    #   debug2
                    #   debug1
                     #   info
                    #   notice
                    #   warning
                    #   error
                    #   log
                    #   fatal
                    #   panic (effectively off)

log_min_duration_statement = 100    # -1 is disabled, 0 logs all statements
                    # and their durations, > 0 logs only
                    # statements running at least this time.

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

# - What to Log -

#debug_print_parse = off
#debug_print_rewritten = off
#debug_print_plan = off
#debug_pretty_print = off
#log_checkpoints = off
#log_connections = off
#log_disconnections = off
#log_duration = off
#log_hostname = off
log_line_prefix = '%t '            # special values:
                    #   %u = user name
                    #   %d = database name
                    #   %r = remote host and port
                    #   %h = remote host
                    #   %p = process ID
                    #   %t = timestamp without milliseconds
                    #   %m = timestamp with milliseconds
                    #   %i = command tag
                    #   %c = session ID
                    #   %l = session line number
                    #   %s = session start timestamp
                    #   %v = virtual transaction ID
                    #   %x = transaction ID (0 if none)
                    #   %q = stop here in non-session
                    #        processes
                    #   %% = '%'
                    # e.g. '<%u%%%d> '
#log_lock_waits = off            # log lock waits >= deadlock_timeout
#log_statement = 'none'            # none, ddl, mod, all
#log_temp_files = -1            # log temporary files equal or larger
                    # than specified size;
                    # -1 disables, 0 logs all temp files
#log_timezone = unknown            # actually, defaults to TZ environment
                    # setting


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

# - Query/Index Statistics Collector -

#track_activities = on
#track_counts = on
#update_process_title = on


# - Statistics Monitoring -

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


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

#autovacuum = on            # Enable autovacuum subprocess?  'on'
                    # requires track_counts to also be on.
#log_autovacuum_min_duration = -1    # -1 disables, 0 logs all actions and
                    # their durations, > 0 logs only
                    # actions running at least that time.
#autovacuum_max_workers = 3        # max number of autovacuum subprocesses
#autovacuum_naptime = 1min        # time between autovacuum runs
#autovacuum_vacuum_threshold = 50    # min number of row updates before
                    # vacuum
#autovacuum_analyze_threshold = 50    # min number of row updates before
                    # analyze
#autovacuum_vacuum_scale_factor = 0.2    # fraction of table size before vacuum
#autovacuum_analyze_scale_factor = 0.1    # fraction of table size before analyze
#autovacuum_freeze_max_age = 200000000    # maximum XID age before forced vacuum
                    # (change requires restart)
#autovacuum_vacuum_cost_delay = 20    # 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
#temp_tablespaces = ''            # a list of tablespace names, '' uses
                    # only default tablespace
#check_function_bodies = on
#default_transaction_isolation = 'read committed'
#default_transaction_read_only = off
#session_replication_role = 'origin'
#statement_timeout = 0            # 0 is disabled
#vacuum_freeze_min_age = 100000000
#xmlbinary = 'base64'
#xmloption = 'content'

# - Locale and Formatting -

datestyle = 'iso, dmy'
#timezone = unknown            # actually, defaults to TZ environment
                    # setting
#timezone_abbreviations = 'Default'     # Select the set of available time zone
                    # abbreviations.  Currently, there are
                    #   Default
                    #   Australia
                    #   India
                    # You can create your own file in
                    # share/timezonesets/.
#extra_float_digits = 0            # min -15, max 2
#client_encoding = sql_ascii        # actually, defaults to database
                    # encoding

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

# default configuration for text search
default_text_search_config = 'pg_catalog.french'

# - Other Defaults -

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


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

#deadlock_timeout = 1s
#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 PostgreSQL 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
#regex_flavor = advanced        # advanced, extended, or basic
#sql_inheritance = on
#standard_conforming_strings = off
#synchronize_seqscans = on

# - Other Platforms and Clients -

#transform_null_equals = off


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

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