New pathhistory setting for the history database directory

[Julien ÉLIE]

Hi all,

In tomorrow's snapshot (inn-CURRENT-20260717.tar.gz), there will be the possibility to set pathhistory in inn.conf for the directory of the history database.
This is a great contribution from Kevin Bowling.

You may want to have your history database in a dedicated partition, so feel free to migrate your history files to a new directory (while INN is not running) and set pathhistory in inn.conf to that directory.
One advantage is to set the following parameter appropriately:

hissqlitepagesize
     The SQLite page size in bytes, applied when the database is  created
     (it  cannot  be  changed  afterwards without rebuilding).  Must be a
     power of two between 512 and 65536.  The default is "4096", matching
     the common filesystem block size so that a random single-row  insert
     or point lookup on the random-MD5 keys touches exactly one block (no
     read-modify-write).   For  best  results, the page size should match
     the underlying storage  block  size:  on  ZFS,  create  a  dedicated
     history  dataset  with  "recordsize=4k"  and  point  the pathhistory
     parameter at it.  A small page on a  coarse-recordsize  ZFS  dataset
     (the  128k  default)  forces read-modify-write on every random write
     and will perform worse, not better.

-- 
Julien ÉLIE

« À l'école, en algèbre, j'étais du genre Einstein. Mais plutôt Franck
   qu'Albert. » (Philippe Geluck)