Indexing is now already finished, not needing as much time as I thought. No more fatal errors for the last ~8000 files.
Only thing I noticed that files with capital letters can not be indexed and also are not displayed by DokuWiki, e.g
http://accesstoinsight.eu/de/lib/authors/nanamoli/PathofPurification2011 . The file exists, but it seems DokuWiki wants to have everything in lower case to make it work.
I also replaced the
{file},
{no} and so on in this
list of files . Replaced, not re-indexed now.
Have not tried to search and find words in them again. Not sure if they are indexed and searchable and if re-indexing would give an error again. Have to test later.
If there are too many problems with the DokuWiki built-in search, which seems like maybe working at the limit here with this number of pages and content, maybe one could look at alternative solutions at some point. I found
this topic in the DokuWiki forum for some ideas. But I think most of the solutions there would not be supported on this server. A really strong and fast search engine for a large scale can probably not exist in only PHP and we can only use PHP on this server.
I will probably not have much time the next days. So maybe will be mostly away for one week at least.