Error message when trying to load all time or 30 days long term data

[jfb]

The issue is with how PHP allocates memory. PHP is doing the work here inside lighttpd. From your debug log:

 2020-05-05 10:00:05: (mod_fastcgi.c.421) FastCGI-stderr: PHP Fatal error:  Allowed memory size of 134217728 bytes exhausted (tried to allocate 4096 bytes) in /var/www/html/admin/api_db.php on line 112
   2020-05-05 10:00:28: (mod_fastcgi.c.421) FastCGI-stderr: PHP Fatal error:  Allowed memory size of 134217728 bytes exhausted (tried to allocate 4096 bytes) in /var/www/html/admin/api_db.php on line 112
   2020-05-05 10:02:22: (mod_fastcgi.c.421) FastCGI-stderr: PHP Fatal error:  Allowed memory size of 134217728 bytes exhausted (tried to allocate 4096 bytes) in /var/www/html/admin/api_db.php on line 112

This thread may have some information of interest:

Querying long term data failed due to limited allowed memory for PHP resulting in "An unknown error occurred with loading the data"

I don't think 30 seconds is a bad number at all for 1.4M queries! I'd have actually anticipated this to be much slower. Imagine what you are doing: You are requesting the data from PHP, a high-level language not really meant for data processing. Dividing your 30 seconds by the 1.4M queries means your Pi-hole is only using 21 µs (yes, micro not milli) per query. This is actually very very fast. But I still see your point and server-side pagination is definitely something we already have impleme…

You can delete (or in the example below, move and save the existing copy) a database, although it is likely yours is not corrupted.

sudo service pihole-FTL stop

sudo mv /etc/pihole/pihole-FTL.db /etc/pihole/pihole-FTL-old.db

sudo service pihole-FTL start