postgresql tuner output

postgresqltuner.pl version 1.0.1
[OK]      I can invoke executables
Connecting to /var/run/postgresql:5432 database database as user 'postgres_admin'...
[OK]      The user account used by me for reporting has superuser rights on this PostgreSQL instance
=====  OS information  =====
[INFO]    OS: linux Version: 4.19.0 Arch: x86_64-linux-gnu-thread-multi
Use of uninitialized value $os_mem in pattern match (m//) at ./postgresqltuner.pl line 318.
Use of uninitialized value $os_mem in pattern match (m//) at ./postgresqltuner.pl line 319.
Use of uninitialized value in numeric eq (==) at ./postgresqltuner.pl line 321.
[BAD]     Memory overcommitment is allowed on the system.  This may lead the OOM Killer to kill at least one PostgreSQL process, DANGER!
[INFO]    sysctl vm.overcommit_ratio=50
[BAD]     vm.overcommit_ratio is too low, you will not be able to use more than (50/100)*RAM+SWAP for applications
[INFO]    Running (probably) directly on a physical machine
[INFO]    Currently used I/O scheduler(s): mq-deadline
=====  General instance informations  =====
-----  PostgreSQL version  -----
[OK]      You are using the latest PostreSQL major version (14.0 (Debian 14.0-1.pgdg110+1))
-----  Uptime  -----
[INFO]    Service uptime: 18d 06m 00s
-----  Databases  -----
[INFO]    Database count (except templates): 3
[INFO]    Database list (except templates): postgres postgres_admin database
-----  Extensions  -----
[INFO]    Number of activated extensions: 1
[INFO]    Activated extensions: plpgsql
[WARN]    Extension pg_stat_statements is disabled in database
-----  Users  -----
[OK]      No user account will expire in less than 7 days
[OK]      No user with password=username
[OK]      Password encryption enabled
-----  Connection information  -----
[INFO]    max_connections: 500
[INFO]    Current used connections: 6 (1.20%)
[INFO]    3 connections are reserved for super user (0.60%)
[INFO]    Average connection age: 15d 05m 00s
-----  Memory usage  -----
[INFO]    Configured work_mem: 4.00 MB
[INFO]    Using an average ratio of work_mem buffers by connection of 150% (use --wmp to change it)
[INFO]    Total work_mem (per connection): 6.00 MB
[INFO]    shared_buffers: 128.00 MB
[INFO]    Track activity reserved size: 0.00 B
[WARN]    maintenance_work_mem is less or equal to its default value.  Increase it to reduce maintenance tasks duration
[INFO]    Max memory usage:
          shared_buffers (128.00 MB)
        + max_connections * work_mem * average_work_mem_buffers_per_connection (500 * 4.00 MB * 150 / 100 = 2.93 GB)
        + autovacuum_max_workers * maintenance_work_mem (3 * 64.00 MB = 192.00 MB)
        + track activity size (0.00 B)
        = 3.24 GB
[INFO]    effective_cache_size: 4.00 GB
[INFO]    Cumulated size of all databases: 59.23 MB
[WARN]    shared_buffer is too big for the total databases size, uselessly using memory
[UNKNOWN] OS total mem unknown: unable to analyse PostgreSQL memory usage
-----  Huge Pages  -----
[WARN]    No Huge Pages available on the system
-----  Logs  -----
[OK]      log_hostname is off: no reverse DNS lookup latency
[WARN]    Log of long queries deactivated.  It will be more difficult to optimize query performance
[OK]      log_statement=none
-----  Two-phase commit  -----
[OK]      Currently there is no two-phase commit transaction
-----  Autovacuum  -----
[OK]      autovacuum is activated
[INFO]    autovacuum_max_workers: 3
-----  Checkpoint  -----
[OK]      checkpoint_completion_target (0.9) OK
[INFO]    Given those settings PostgreSQL may (depending on its workload) ask the kernel to write (to the storage) up to 1024.00 MB in a timeframe lasting 270 seconds <=> 3.79 MB bytes/second during this timeframe.  You may want to check that your storage is able to cope with this, along with all other I/O (non-writing queries, other software...) operations potentially active during this timeframe.  If this seems inadequate check max_wal_size, checkpoint_timeout and checkpoint_completion_target
-----  Storage  -----
[OK]      fsync is on
[OK]      synchronize_seqscans is on
-----  WAL  -----
-----  Planner  -----
[OK]      I/O cost settings are set at their default values
[WARN]    With SSD storage, set random_page_cost=seq_page_cost to help the planner prefer index scans
[BAD]     Some plan features are disabled: enable_partitionwise_aggregate,enable_partitionwise_join
=====  Database information for database databse  =====
-----  Database size  -----
[INFO]    Database database total size: 26.12 MB
[INFO]    Database database tables size: 14.34 MB (54.90%)
[INFO]    Database database indexes size: 11.78 MB (45.10%)
-----  Tablespace location  -----
[OK]      No tablespace in PGDATA
-----  Shared buffer hit rate  -----
[INFO]    shared_buffer_heap_hit_rate: 100.00%
[INFO]    shared_buffer_toast_hit_rate: 99.97%
[INFO]    shared_buffer_tidx_hit_rate: 100.00%
[INFO]    shared_buffer_idx_hit_rate: 100.00%
[INFO]    This is too high.  If this PostgreSQL instance was recently used as it usually is and was not stopped since, then you may reduce shared_buffer
-----  Indexes  -----
[OK]      No invalid index
[WARN]    117 indexes were not used since the last statistics run
-----  Procedures  -----
[OK]      No procedures with default costs

=====  Configuration advice  =====
-----  extension  -----
[LOW] Enable pg_stat_statements in database database to collect statistics on all queries (not only those longer than log_min_duration_statement)
-----  index  -----
[MEDIUM] You have unused indexes in the database since the last statistics run.  Please remove them if they are rarely or not used
-----  planner  -----
[MEDIUM] Set random_page_cost=seq_page_cost on SSD storage
-----  system  -----
[HIGH] set vm.overcommit_memory=2 in /etc/sysctl.conf and invoke  sysctl -p /etc/sysctl.conf  to enforce it.  This will disable memory overcommitment and avoid having a PostgreSQL process killed by the OOM killer