pgBackRest version: 2.51
PostgreSQL version: 13.3
OS: Ubuntu 20.04

archive_mode = on
archive_command = 'pgbackrest --stanza=my_stanza archive-push %p'
listen_addresses = *
max_wal_senders = 10 
wal_level = replica
port = 5433

have a configuration where I take backups on a standby server. In case of any problems in the database, I was asked to be able to restore to 15 minutes ago. So I set up the setup as follows;
Full backup one day a week,
Diff backup once a day,
Incr backup every 15 minutes every day.

But I think there is a problem with the setup. First of all, is it necessary to take a backup every 15 minutes to go back to 15 minutes ago, or is it enough for me to take a full backup once a week and 1 incr backup once a day to go back to 15 minutes ago?

My configs are as follows;

Conf;

pg-backup;

[global]
repo1-path=/mnt/dbbackup
repo1-retention-full=2
process-max=2
start-fast=y
log-level-console=info
log-level-file=info
backup-standby=y

[global:archive-push]
compress-type=zst
compress-level=3

[my_stanza]
pg1-host=primary_hostname
pg1-path=/data
pg1-port=5433
pg2-host=standby_hostname
pg2-path=/data
pg2-port=5433

pg-primary;
[global]
log-level-file=info
repo1-host=backup_hostname
start-fast=y
archive-async = y
process-max = 2
spool-path = /var/spool/pgbackrest

[global:archive-get]
process-max=4

[global:archive-push]
process-max=4


[my_stanza]
pg1-path=/data
pg1-port=5433

pg-standby
[global]
log-level-file=info
repo1-host=backup_hostname
start-fast=y
process-max = 2
spool-path = /var/spool/pgbackrest

[my_stanza]
pg1-path=/data
pg1-port=5433

I don’t know if there is a problem with the script I installed or with my pgbackrest config files.

In addition, I tried to install the block incr structure of pgbackrest from the previous topic, but it had no effect: link

I set this parameter on both primary and standby server but it had no effect;

Last full backup and reference incr backups;

8.9G    20240613-110729F
1.2G    20240613-110729F_20240613-111503I
5.1G    20240613-110729F_20240613-113003I
4.2G    20240613-110729F_20240613-114504I
4.2G    20240613-110729F_20240613-120004I

Total size of incr backups taken with the previous full backup reference;

4.0G    20240604-172054F_20240613-103004I
6.9G    20240604-172054F_20240613-104504I
4.0G    20240604-172054F_20240613-110004I
739G    total

The size of my database cluster is only 12 GB

What I need to do?

Thanks.