Hello, I'm inquiring because of using a lot of memory in each session.

1. A description of what you are trying to achieve and what results you expect :

We set shared_buffer = 70GB, max_connections = 300, work_mem = 300MB.

We thought the session memory could be adjusted with the work_mem variable, but no. noticed that each session consumed more than 500MB.

We're wondering what are the things that are occupied in session memory and if there is a way to organize these in each session and return the memory.

2. PostgreSQL version number you are running:

PostgreSQL 15.3 (Ubuntu 15.3-1.pgdg22.04+~20230706.1614.g25624c5) on aarch64-unknown-linux-gnu, compiled by gcc (Ubuntu 11.3.0-1ubuntu1~22.04.1) 11.3.0, 64-bit

3. How you installed PostgreSQL:

We have downloaded debs on https://apt.postgresql.org/pub/repos/apt/pool/main/p/postgresql-15/

and installed them.

4. Changes made to the settings in the postgresql.conf file:

name	current_setting	source
archive_command	cp /data/PG15/pg_wal/%f /archive_data/%f	configuration file
archive_mode	on	configuration file
auto_explain.log_analyze	on	configuration file
auto_explain.log_buffers	on	configuration file
autovacuum_analyze_scale_factor	0	configuration file
autovacuum_analyze_threshold	100000000	configuration file
autovacuum_freeze_max_age	500000000	configuration file
autovacuum_max_workers	3	configuration file
autovacuum_naptime	1min	configuration file
autovacuum_vacuum_cost_delay	50ms	configuration file
autovacuum_vacuum_insert_scale_factor	0	configuration file
autovacuum_vacuum_insert_threshold	30000	configuration file
autovacuum_vacuum_scale_factor	0	configuration file
autovacuum_vacuum_threshold	5000	configuration file
checkpoint_warning	1h	configuration file
client_encoding	UTF8	client
DateStyle	ISO, MDY	client
deadlock_timeout	100ms	configuration file
default_text_search_config	pg_catalog.english	configuration file
dynamic_shared_memory_type	posix	configuration file
effective_cache_size	48GB	configuration file
effective_io_concurrency	600	configuration file
enable_mergejoin	off	configuration file
enable_seqscan	off	configuration file
extra_float_digits	3	session
jit	off	configuration file
lc_messages	en_US.UTF-8	configuration file
lc_monetary	en_US.UTF-8	configuration file
lc_numeric	en_US.UTF-8	configuration file
lc_time	en_US.UTF-8	configuration file
listen_addresses	*	configuration file
log_autovacuum_min_duration	10ms	configuration file
log_checkpoints	on	configuration file
log_destination	stderr, csvlog	configuration file
log_directory	/data/log	configuration file
log_filename	postgresql-%a.log	configuration file
log_line_prefix	%m [%p][%u][%h]	configuration file
log_lock_waits	on	configuration file
log_min_duration_statement	1500ms	user
log_min_messages	warning	configuration file
log_rotation_age	1d	configuration file
log_rotation_size	0	configuration file
log_timezone	Asia/Seoul	configuration file
log_truncate_on_rotation	on	configuration file
logging_collector	on	configuration file
maintenance_work_mem	200MB	configuration file
max_connections	300	configuration file
max_locks_per_transaction	2000	configuration file
max_parallel_workers	0	configuration file
max_parallel_workers_per_gather	0	configuration file
max_wal_size	2GB	configuration file
max_worker_processes	50	configuration file
min_wal_size	1GB	configuration file
password_encryption	md5	configuration file
plan_cache_mode	force_custom_plan	configuration file
port	45432	configuration file
restore_command	mv -f /archive_data/%f /data/PG15/pg_wal/%f	configuration file
shared_buffers	70GB	configuration file
shared_preload_libraries	pg_hint_plan, pg_cron, pg_stat_statements, auto_explain	configuration file
superuser_reserved_connections	6	configuration file
tcp_keepalives_idle	30	configuration file
tcp_keepalives_interval	1	configuration file
TimeZone	Asia/Seoul	client
vacuum_cost_limit	1000	configuration file
wal_buffers	1GB	configuration file
wal_compression	zstd	configuration file
wal_sender_timeout	10min	configuration file
work_mem	200MB	configuration file

5. Operating system and version:

Distributor ID: Ubuntu

Description: Ubuntu 22.04.2 LTS

Release: 22.04

Codename: jammy

6. What program you're using to connect to PostgreSQL:

Just do on Linux kernel