[wp-hackers] What were the shared hosting issues with persistent file cache prior to WP 2.5 ?

[Kaloyan Tsvetkov]

Hi,

I am doing some research on file-based caching and I read that persistent
cache was removed from WP since 2.5 and was replaced with in-memory one. The
reason for that were that the WP implementation was hardly introducing any
performance boost and that there were some issues with shared hosting.

Does someone recall what these issues were, or at least where I can read
about them ?

I've checked the links from here:

http://codex.wordpress.org/Function_Reference/WP_Cache#Persistent_Caching

and it seems that all file-based cache solutions (even W3 has one in the
W3_Cache_File class) create a separate file for each cached entry. Was this
the issue that lead to performance degradation ?

Thanks in advance,
K.