I have been looking for some open source search engine software/library that can be used in shared hosting, I know for sure services like Lucene, Lucene.Net, Sphinx or Xapian cannot be used in shared hosting as they require some installation or restart.
Looking at wikipedia article(see here) I found out these open source search engine solution.
Apache Solr
BaseX
Clusterpoint Server (freeware licence for a single-server)
DataparkSearch
ElasticSearch (Apache License, Version 2.0)
Ferret
ht://Dig
Hyper Estraier
KinoSearch
Lemur/Indri
Lucene
mnoGoSearch
Sphinx
Swish-e
Xapian
And as I searched around none of them can be used in shared hosting. I think i have to stick with MySQL FULL TEXT Search while i am on shared hosting.
So any suggestion for search engine alternative for shared hosting.
As long as your host supports PHP 5+, you will be able to use Zend Framework’s Lucene implementation. It supports Lucene index format versions 1.4 – 2.3. Since the index is written directly to the filesystem, it should support any host that allows you filesystem access (most do).
Documentation: http://framework.zend.com/manual/en/zend.search.lucene.html
That being said, you could also simply use the MySQL full text search. It isn’t without limitations and it isn’t the most scalable solution, but you are talking about shared hosting which is generally not the most scalable environment anyhow so I wouldn’t worry about it too much given that.
PostgreSQL is also an option and is recommended if you go with a hosting provider such as Heroku (you can do PHP on Heroku).
Further, depending on your search needs, you could simply read up on inverted indexes and roll your own simply implementation.
Finally, I wanted to mention that you didn’t actually list out which search features you were interested in.
Without listing the features you want, it will always be difficult for someone to make an accurate (and unbiased) recommendation. That being said, you’ll likely be fine with the basics.