libpq message of dispatch

trace_pq.sh

## the example of the dispatch message on QD side

# PasswordMessage
To backend> Msg
To backend> p user ubuntu database postgres options -c gp_qd_hostname=127.0.1.1 -c gp_qd_port=5432 -c allow_in_place_tablespaces=false -c allow_segment_DML=false -c allow_system_table_mods=false -c array_nulls=true -c backend_flush_after=0 -c backslash_quote=safe_encoding -c bytea_output=hex -c client_min_messages=notice -c commit_delay=0 -c commit_siblings=5 -c coredump_on_memerror=false -c DateStyle=ISO,\ MDY -c Debug_appendonly_print_append_block=false -c debug_appendonly_print_blockdirectory=false -c debug_appendonly_print_compaction=false -c debug_appendonly_print_datumstream=false -c debug_appendonly_print_delete=false -c debug_appendonly_print_insert=false -c debug_appendonly_print_insert_tuple=false -c Debug_appendonly_print_read_block=false -c debug_appendonly_print_scan=false -c debug_appendonly_print_scan_tuple=false -c debug_appendonly_print_segfile_choice=false -c debug_appendonly_print_storage_headers=false -c debug_appendonly_print_verify_write_block=false -c debug_appendonly_print_visimap=false -c debug_appendonly_use_no_toast=false -c default_table_access_method=heap -c default_tablespace= -c execute_pruned_plan=true -c explain_memory_verbosity=suppress -c force_parallel_mode=off -c gin_fuzzy_search_limit=0 -c gin_pending_list_limit=4096 -c gp_allow_date_field_width_5digits=false -c gp_appendonly_compaction=true -c gp_appendonly_compaction_threshold=10 -c gp_appendonly_verify_block_checksums=true -c gp_appendonly_verify_write_block=false -c gp_blockdirectory_entry_min_range=0 -c gp_blockdirectory_minipage_size=161 -c gp_debug_linger=0 -c gp_default_storage_options=blocksize=32768,compresstype=none,checksum=true -c gp_disable_tuple_hints=true -c gp_enable_interconnect_aggressive_retry=true -c gp_enable_segment_copy_checking=true -c gp_external_enable_filter_pushdown=true -c gp_hashjoin_tuples_per_bucket=5 -c gp_ignore_error_table=false -c gp_indexcheck_insert=0 -c gp_initial_bad_row_limit=1000 -c gp_interconnect_address_type=unicast -c gp_interconnect_cache_future_packets=true -c gp_interconnect_debug_retry_interval=10 -c gp_interconnect_default_rtt=20 -c gp_interconnect_fc_method=loss -c gp_interconnect_full_crc=false -c gp_interconnect_log_stats=false -c gp_interconnect_min_retries_before_timeout=100 -c gp_interconnect_min_rto=20 -c gp_interconnect_queue_depth=4 -c gp_interconnect_setup_timeout=7200 -c gp_interconnect_snd_queue_depth=2 -c gp_interconnect_tcp_listener_backlog=256 -c gp_interconnect_timer_checking_period=20 -c gp_interconnect_timer_period=5 -c gp_interconnect_transmit_timeout=3600 -c gp_interconnect_type=udpifc -c gp_log_endpoints=false -c gp_log_interconnect=terse -c gp_log_resgroup_memory=false -c gp_log_resqueue_memory=false -c gp_log_stack_trace_lines=true -c gp_log_suboverflow_statement=false -c gp_max_packet_size=8192 -c gp_motion_slice_noop=0 -c gp_quicklz_fallback=false -c gp_resgroup_debug_wait_queue=true -c gp_resgroup_memory_policy_auto_fixed_mem=100 -c gp_resqueue_memory_policy_auto_fixed_mem=100 -c gp_resqueue_print_operator_memory_limits=false -c gp_select_invisible=false -c gp_sessionstate_loglevel=debug1 -c gp_snapshotadd_timeout=30 -c gp_udp_bufsize_k=0 -c gp_udpic_dropacks_percent=0 -c gp_udpic_dropseg=-2 -c gp_udpic_dropxmit_percent=0 -c gp_udpic_fault_inject_bitmap=0 -c gp_udpic_fault_inject_percent=0 -c gp_udpic_network_disable_ipv6=0 -c gp_workfile_caching_loglevel=debug1 -c gp_workfile_compression=false -c gp_workfile_limit_files_per_query=100000 -c gp_workfile_limit_per_query=0 -c gp_write_shared_snapshot=false -c ignore_checksum_failure=false -c ignore_system_indexes=false -c IntervalStyle=postgres -c jit=false -c jit_above_cost=100000.000000 -c jit_debugging_support=false -c jit_dump_bitcode=false -c jit_expressions=true -c jit_inline_above_cost=500000.000000 -c jit_optimize_above_cost=500000.000000 -c jit_profiling_support=false -c jit_tuple_deforming=true -c lc_messages=en_US.UTF-8 -c lc_monetary=en_US.UTF-8 -c lc_numeric=en_US.UTF-8 -c lc_time=en_US.UTF-8 -c lock_timeout=0 -c log_dispatch_stats=false -c log_duration=false -c log_error_verbosity=default -c log_executor_stats=false -c log_min_duration_statement=-1 -c log_min_error_statement=error -c log_min_messages=warning -c log_statement_stats=false -c maintenance_work_mem=65536 -c max_parallel_workers_per_gather=2 -c max_statement_mem=2048000 -c memory_profiler_dataset_id=none -c memory_profiler_dataset_size=0 -c memory_profiler_query_id=none -c memory_profiler_run_id=none -c optimizer_jit_above_cost=7500.000000 -c optimizer_jit_inline_above_cost=37500.000000 -c optimizer_jit_optimize_above_cost=37500.000000 -c pljava_classpath= -c pljava_release_lingering_savepoints=false -c pljava_statement_cache_size=0 -c pljava_vmoptions= -c readable_external_table_timeout=0 -c row_security=true -c search_path="$user",\ public -c seed=0.000000 -c statement_mem=128000 -c statement_timeout=0 -c stats_queue_level=false -c synchronize_seqscans=true -c tcp_keepalives_count=0 -c tcp_keepalives_idle=0 -c tcp_keepalives_interval=0 -c tcp_user_timeout=0 -c temp_buffers=1024 -c temp_tablespaces= -c test_copy_qd_qe_split=false -c TimeZone=Asia/Shanghai -c timezone_abbreviations=Default -c vacuum_cleanup_index_scale_factor=0.100000 -c vacuum_cost_delay=0.000000 -c vacuum_cost_page_dirty=20 -c vacuum_cost_page_hit=1 -c vacuum_cost_page_miss=2 -c vacuum_freeze_min_age=50000000 -c vacuum_freeze_table_age=150000000 -c vacuum_multixact_freeze_min_age=5000000 -c vacuum_multixact_freeze_table_age=150000000 -c verify_gpfdists_cert=true -c vmem_process_interrupt=false -c wal_sender_timeout=300000 -c work_mem=32768 -c zero_damaged_pages=falseclient_encodingUTF8gpqeid2;744706450347864;true;2;4;6
To backend> Msg complete, length 5680
# Authentication message (e.g. AuthenticationOk)
From backend> R
From backend (#4)> 8
From backend (#4)> 0

# ParameterStatus
From backend> S
From backend (#4)> 22
From backend> "application_name"
From backend> ""
pqSaveParameterStatus: 'application_name' = ''
From backend> S
From backend (#4)> 25
From backend> "client_encoding"
From backend> "UTF8"
pqSaveParameterStatus: 'client_encoding' = 'UTF8'
From backend> S
From backend (#4)> 23
From backend> "DateStyle"
From backend> "ISO, MDY"
pqSaveParameterStatus: 'DateStyle' = 'ISO, MDY'
From backend> S
From backend (#4)> 32
From backend> "gp_autovacuum_scope"
From backend> "catalog"
pqSaveParameterStatus: 'gp_autovacuum_scope' = 'catalog'
From backend> S
From backend (#4)> 68
From backend> "gp_server_version"
From backend> "7.0.0-alpha.0+dev.18905.ga002381ee8 build dev"
pqSaveParameterStatus: 'gp_server_version' = '7.0.0-alpha.0+dev.18905.ga002381ee8 build dev'
From backend> S
From backend (#4)> 25
From backend> "integer_datetimes"
From backend> "on"
pqSaveParameterStatus: 'integer_datetimes' = 'on'
From backend> S
From backend (#4)> 27
From backend> "IntervalStyle"
From backend> "postgres"
pqSaveParameterStatus: 'IntervalStyle' = 'postgres'
From backend> S
From backend (#4)> 20
From backend> "is_superuser"
From backend> "on"
pqSaveParameterStatus: 'is_superuser' = 'on'
From backend> S
From backend (#4)> 25
From backend> "server_encoding"
From backend> "UTF8"
pqSaveParameterStatus: 'server_encoding' = 'UTF8'
From backend> S
From backend (#4)> 25
From backend> "server_version"
From backend> "12.12"
pqSaveParameterStatus: 'server_version' = '12.12'
From backend> S
From backend (#4)> 33
From backend> "session_authorization"
From backend> "ubuntu"
pqSaveParameterStatus: 'session_authorization' = 'ubuntu'
From backend> S
From backend (#4)> 35
From backend> "standard_conforming_strings"
From backend> "on"
pqSaveParameterStatus: 'standard_conforming_strings' = 'on'
From backend> S
From backend (#4)> 27
From backend> "TimeZone"
From backend> "Asia/Shanghai"
pqSaveParameterStatus: 'TimeZone' = 'Asia/Shanghai'

# BackendKeyData
From backend> K
From backend (#4)> 12
From backend (#4)> 38598
From backend (#4)> 1273667237
From backend> S
From backend (#4)> 32
From backend> "qe_listener_port"
From backend> "3622830080"
pqSaveParameterStatus: 'qe_listener_port' = '3622830080'
From backend> k
From backend (#4)> 12
From backend> x
From backend (#4)> 5
From backend>

# ReadyForQuery
From backend> Z
From backend (#4)> 5
# EmptyQueryResponse
From backend> I

# gp's 'M' message with the dispatched query
To backend> PQsendGpQuery_shared M, length 164

# RowDescription
From backend> T
From backend (#4)> 28
From backend (#2)> 1
From backend> "gid"
From backend (#4)> 12728
From backend (#2)> 2
From backend (#4)> 25
From backend (#2)> 65535
From backend (#4)> -1
From backend (#2)> 0

# CommandComplete
From backend> C
From backend (#4)> 13
From backend> "SELECT 0"
From backend> k
From backend (#4)> 12
From backend> x
From backend (#4)> 5
From backend>

# ReadyForQuery
From backend> Z
From backend (#4)> 5
From backend> Z
From backend (#4)> 5
From backend> Z
From backend (#4)> 5
# EmptyQueryResponse
From backend> I

# Terminate message (QD quits)
To backend> Msg X
To backend> Msg complete, length 5