Parameter Categories

This document describes the categories of all system configuration parameters in YMatrix.

The complete list of categories is as follows:

File Locations
Connections and Authentication
Client Connection Default Parameters
Error Reporting and Logging
Resource Consumption
Query Tuning
Runtime Statistics
Automatic Vacuum
Database Table
Lock Management
Resource Management
YMatrix Database Cluster
Write-Ahead Log
Replication
PL/Java Parameters
Version and Platform Compatibility

File Locations

external_pid_file
data_directory
hba_file
ident_file

Connections and Authentication

Connection Settings

bonjour
bonjour_name
gp_connection_send_timeout
listen_addresses
max_connections
port
superuser_reserved_connections
unix_socket_directories
unix_socket_group
unix_socket_permissions
tcp_keepalives_count
tcp_keepalives_idle
tcp_keepalives_interval
tcp_user_timeout

Security and Authentication

authentication_timeout
db_user_namespace
krb_caseins_users
krb_server_keyfile
password_encryption

SSL

ssl
ssl_ca_file
ssl_cert_file
ssl_ciphers
ssl_crl_file
ssl_dh_params_file
ssl_ecdh_curve
ssl_key_file
ssl_max_protocol_version
ssl_min_protocol_version
ssl_passphrase_command
ssl_passphrase_command_supports_reload
ssl_prefer_server_ciphers

Client Connection Default Parameters

Statement Behavior

bytea_output
check_function_bodies
client_min_messages
default_tablespace
default_transaction_deferrable
default_transaction_read_only
gin_fuzzy_search_limit
gin_pending_list_limit
gp_vmem_idle_resource_timeout
idle_in_transaction_session_timeout
lc_collate
lc_ctype
lock_timeout
row_security
search_path
session_replication_role
statement_timeout
temp_tablespaces
vacuum_cleanup_index_scale_factor
vacuum_freeze_min_age
vacuum_freeze_table_age
vacuum_multixact_freeze_min_age
vacuum_multixact_freeze_table_age

Locale and Formatting

client_encoding
datestyle
default_text_search_config
extra_float_digits
intervalstyle
lc_messages
lc_monetary
lc_numeric
lc_time
timezone
timezone_abbreviations

Multiple settings allow preloading shared libraries into the server to add functionality or improve performance. For example, the $libdir/mylib setting may cause mylib.so (or mylib.sl on some platforms) to be preloaded from the standard library directory. These settings differ in when they take effect and the privileges required to change them.

YMatrix procedural language libraries can be preloaded using the $libdir/plXXX syntax, where XXX is pgsql, perl, tcl, or python.

Only shared libraries specifically designed for use with YMatrix can be loaded this way. Each YMatrix-supported library contains a "magic block" that is checked for compatibility. As a result, non-YMatrix libraries cannot be loaded in this manner. You may use operating system tools (such as LD_PRELOAD) to load them instead.

Refer to the documentation of specific modules for recommended loading methods.

jit_provider
local_preload_libraries
session_preload_libraries
shared_preload_libraries

Other Default Options

dynamic_library_path

Error Reporting and Logging

Where to Log

event_source
logging_collector
log_destination
log_directory
log_file_mode
log_filename
log_rotation_age
log_rotation_size
log_truncate_on_rotation
syslog_facility
syslog_ident
syslog_sequence_numbers
syslog_split_messages

When to Log

gp_interconnect_debug_retry_interval
log_min_duration_statement
log_min_error_statement
log_min_messages
log_statement_sample_rate
log_transaction_sample_rate
optimizer_minidump

What to Log

application_name
debug_pretty_print
debug_print_parse
debug_print_plan
debug_print_prelim_plan
debug_print_rewritten
debug_print_slice_table
gp_debug_linger
gp_log_format
gp_log_interconnect
gp_reraise_signal
log_checkpoints
log_connections
log_disconnections
log_dispatch_stats
log_duration
log_error_verbosity
log_hostname
log_line_prefix
log_lock_waits
log_replication_commands
log_statement
log_temp_files
log_timezone

Process Titles

cluster_name
update_process_title

Resource Consumption

Memory

autovacuum_work_mem
dynamic_shared_memory_type
gp_resource_group_memory_limit
gp_vmem_protect_limit
gp_vmem_protect_segworker_cache_limit
gp_workfile_limit_files_per_query
gp_workfile_limit_per_query
gp_workfile_limit_per_segment
huge_pages
maintenance_work_mem
max_prepared_transactions
max_stack_depth
mx_dump_mctx_threshold
mx_dump_print_filter
shared_buffers
shared_memory_type
temp_buffers
work_mem

Disk

temp_file_limit

Kernel Resource Usage

max_files_per_process

Cost-Based Vacuum Delay

During execution of VACUUM and ANALYZE, the system maintains an internal counter tracking estimated I/O costs of various operations. When the accumulated cost reaches a limit defined by vacuum_cost_limit, the process performing the operation sleeps for a short time as specified by vacuum_cost_delay. The counter is then reset before execution resumes.

This feature allows administrators to reduce the I/O impact of these commands on concurrent database activity. In many cases, it is not critical that maintenance commands such as VACUUM and ANALYZE complete quickly. What matters is that they do not significantly affect the system's ability to perform other database operations. Cost-based vacuum delay provides a way for administrators to ensure this.

vacuum_cost_delay
vacuum_cost_limit
vacuum_cost_page_dirty
vacuum_cost_page_hit
vacuum_cost_page_miss

Asynchronous Behavior

backend_flush_after
effective_io_concurrency
max_parallel_maintenance_workers
max_parallel_workers
max_parallel_workers_per_gather
max_worker_processes
old_snapshot_threshold

Query Tuning

Postgres Query Optimizer Operator Control Parameters

enable_bitmapscan
enable_groupagg
enable_hashagg
enable_hashjoin
enable_indexonlyscan
enable_indexscan
enable_mars2aggscan
enable_material
enable_mergejoin
enable_nestloop
enable_parallel_append
enable_parallel_hash
enable_partition_pruning
enable_partitionwise_aggregate
enable_partitionwise_join
enable_seqscan
enable_sort
enable_tidscan
gp_enable_agg_distinct
gp_enable_agg_distinct_pruning
gp_enable_direct_dispatch
gp_enable_fast_sri
gp_enable_multiphase_agg
gp_enable_preunique
gp_enable_relsize_collection
gp_enable_sort_distinct
gp_enable_sort_limit
gp_selectivity_damping_for_joins
gp_selectivity_damping_for_scans
min_parallel_index_scan_size
min_parallel_table_scan_size
parallel_leader_participation

Postgres Query Optimizer Cost Calculation Parameters

cpu_index_tuple_cost
cpu_operator_cost
cpu_tuple_cost
cursor_tuple_fraction
effective_cache_size
gp_appendonly_random_page_cost
gp_compressed_random_page_cost
gp_motion_cost_per_row
gp_segments_for_planner
parallel_setup_cost
parallel_tuple_cost
random_page_cost
seq_page_cost

Postgres Genetic Query Optimization (GEQO) Parameters

GEQO is an algorithm that uses a heuristic search method for query planning. It reduces planning time for complex queries involving multiple table joins, at the expense of potentially suboptimal plans compared to exhaustive search methods.

geqo
geqo_effort
geqo_generations
geqo_pool_size
geqo_seed
geqo_selection_bias
geqo_threshold

Database Statistics Sampling Parameters

These parameters control the data sampling size for ANALYZE operations. Adjusting them affects statistics collection across the entire system. You can use the ALTER TABLE SET STATISTICS clause to configure statistics collection for specific tables and columns.

default_statistics_target

Sort Operator Configuration Parameters

gp_enable_sort_limit

Aggregate Operator (Agg) Configuration Parameters

gp_enable_agg_distinct
gp_enable_agg_distinct_pruning
gp_enable_multiphase_agg
gp_enable_preunique
gp_workfile_compression
mx_pullup_agg_proj_and_qual

Join Operator Configuration Parameters

join_collapse_limit
gp_adjust_selectivity_for_outerjoins
gp_hashjoin_tuples_per_bucket
gp_workfile_compression

Query Plan Execution

gp_max_slices
plan_cache_mode

JIT (Just-In-Time) Configuration Parameters

jit
jit_above_cost
jit_debugging_support
jit_dump_bitcode
jit_expressions
jit_inline_above_cost
jit_optimize_above_cost
jit_profiling_support
jit_tuple_deforming

Greenplum ORCA Optimizer Configuration Parameters

gp_enable_relsize_collection
optimizer
optimizer_analyze_root_partition
optimizer_array_expansion_threshold
optimizer_control
optimizer_cost_model
optimizer_cte_inlining_bound
optimizer_dpe_stats
optimizer_enable_associativity
optimizer_enable_dml
optimizer_enable_indexonlyscan
optimizer_enable_multiple_distinct_aggs
optimizer_force_agg_skew_avoidance
optimizer_force_multistage_agg
optimizer_force_three_stage_scalar_dqa
optimizer_join_arity_for_associativity_commutativity
optimizer_join_order
optimizer_join_order_threshold
optimizer_mdcache_size
optimizer_metadata_caching
optimizer_parallel_union
optimizer_penalize_broadcast_threshold
optimizer_penalize_skew
optimizer_print_optimization_stats
optimizer_sort_factor

Runtime Filter Optimization Parameters

mx_enable_runtime_filter
mx_runtime_join_ratio
mx_runtime_max_filter_per_query
mx_runtime_max_inner_rows
mx_runtime_max_intent_level
mx_runtime_min_outer_rows
mx_runtime_scan_ratio

Vectorized Execution Engine Parameters

matrix.enable_mxvector
matrix.enable_mxv_aggregate
matrix.enable_mxv_hash_aggregate
matrix.enable_mxv_append
matrix.enable_mxv_motion
matrix.enable_mxv_presort_aggregate
matrix.enable_mxv_root
matrix.enable_mxv_sort
matrix.enable_mxv_strict_mode
matrix.enable_mxv_fallback_expression
matrix.enable_mxv_limit
matrix.enable_mxv_window
matrix.enable_mxv_subqueryscan
matrix.enable_mxv_hash_join
matrix.enable_mxv_hash_join_advanced_hashmap
matrix.enable_mxv_aggscan
matrix.enable_mxv_heap_adapter
matrix.enable_mxv_indexscan

Runtime Statistics

ANALYZE Statistics on Database Content

default_statistics_target

Query and Index Statistics Collector

These parameters control the server-wide statistics collection feature. When enabled, the collected data can be accessed through the pg_stat and pg_statio system view families.

track_activities
track_activity_query_size
track_counts
track_functions
track_io_timing
stats_queue_level
stats_temp_directory

Statistics Monitoring

log_executor_stats
log_parser_stats
log_planner_stats
log_statement_stats

Automatic Statistics Collection Parameters

gp_autostats_mode
gp_autostats_mode_in_functions
gp_autostats_on_change_threshold
log_autostats

Automatic Vacuum Parameters

autovacuum
autovacuum_analyze_scale_factor
autovacuum_analyze_threshold
autovacuum_freeze_max_age
autovacuum_max_workers
autovacuum_multixact_freeze_max_age
autovacuum_naptime
autovacuum_vacuum_cost_delay
autovacuum_vacuum_cost_limit
autovacuum_vacuum_scale_factor
autovacuum_vacuum_threshold
log_autovacuum_min_duration

Database Table

HEAP Table / Append-Optimized Table (AO) Parameters

default_table_access_method
gp_create_table_random_default_distribution
gp_default_storage_options
gp_appendonly_compaction
gp_appendonly_compaction_threshold
gp_safefswritesize

MARS2 Table-Level Parameters

compress_threshold
level0_merge_threshold
level0_upgrade_size
level1_upgrade_size
sortheap_automerge_threshold
sortheap_sort_mem
sortheap_sort_mem_core

MARS3 Table-Level Parameters

compress_threshold
level_size_amplifier
prefer_load_mode
rowstore_runsize

MARS3 Degraded Storage Parameters

matrixts.enable_object_cache
mars3.degrade_credential_update_interval
mars3.degrade_probe_interval
mars3.enable_object_prefetch
mars3.enable_objectstore

External Table Parameters

gp_external_enable_exec
gp_external_enable_filter_pushdown
gp_external_max_segs
gp_initial_bad_row_limit
gp_reject_percent_threshold
mx_discard_gpfdist_data
readable_external_table_timeout
writable_external_table_bufsize
verify_gpfdists_cert

Lock Management

--- SPLIT ---

Lock Management Parameters

deadlock_timeout
gp_enable_global_deadlock_detector
max_locks_per_transaction
max_pred_locks_per_page
max_pred_locks_per_relation
max_pred_locks_per_transaction

Resource Management Parameters

Resource Groups

gp_resgroup_memory_policy
gp_resource_group_cpu_limit
gp_resource_group_cpu_priority
gp_resource_group_queuing_timeout
gp_resource_manager
memory_spill_ratio
mx_cgroup_v1_base

Resource Queues

gp_resqueue_memory_policy
gp_resqueue_priority
gp_resqueue_priority_cpucores_per_segment
gp_resqueue_priority_sweeper_interval
gp_vmem_protect_limit
max_resource_portals_per_transaction
max_resource_queues
max_statement_mem
resource_cleanup_gangs_on_wait
resource_select_only
runaway_detector_activation_percent
statement_mem

YMatrix Database Cluster Parameters

Cluster Configuration Parameters

enable_drop_matrixdb_extension
mx_create_table_default_segments
mx_default_segment_set
mx_ha_provider
mx_postmaster_pdeath_signal

Mirror Configuration Parameters

repl_catchup_within_range
wait_for_replication_threshold

Interconnect Configuration Parameters

gp_interconnect_fc_method
gp_interconnect_proxy_addresses
gp_interconnect_queue_depth
gp_interconnect_setup_timeout
gp_interconnect_snd_queue_depth
gp_interconnect_transmit_timeout
gp_interconnect_type
gp_max_packet_size
gp_segment_connect_timeout
mx_interconnect_compress
mx_generic_packet_rtt

Failover Configuration Parameters

gp_fts_probe_retries
gp_fts_probe_interval
gp_fts_probe_timeout

Dispatch Configuration Parameters

gp_cached_segworkers_threshold
gp_set_proc_affinity

Distributed Transaction Management Parameters

gp_max_local_distributed_cache

Read-only Parameters

gp_command_count
gp_contentid
gp_dbid
gp_role
gp_session_id
gp_server_version
gp_server_version_num

Write Ahead Log Parameters

Settings

commit_delay
commit_siblings
full_page_writes
fsync
synchronous_commit
wal_buffers
wal_compression
wal_init_zero
wal_level
wal_log_hints
wal_recycle
wal_sync_method
wal_writer_delay
wal_writer_flush_after

Checkpoints

checkpoint_completion_target
checkpoint_flush_after
checkpoint_timeout
checkpoint_warning
max_wal_size
min_wal_size

Archiving

archive_command
archive_mode
archive_timeout

Archive Recovery

These parameters are used only in recovery mode. You must reset them if you plan to perform any subsequent recovery operations.

"Recovery" includes running the server as a standby server or performing point-in-time recovery. Typically, standby mode is used for high availability and/or read scalability, while point-in-time recovery is used to recover from data loss.