Comparison of full text search engine – Lucene, Sphinx, Postgresql, MySQL? [closed]

Good to see someone’s chimed in about Lucene – because I’ve no idea about that.

Sphinx, on the other hand, I know quite well, so let’s see if I can be of some help.

  • Result relevance ranking is the default. You can set up your own sorting should you wish, and give specific fields higher weightings.
  • Indexing speed is super-fast, because it talks directly to the database. Any slowness will come from complex SQL queries and un-indexed foreign keys and other such problems. I’ve never noticed any slowness in searching either.
  • I’m a Rails guy, so I’ve no idea how easy it is to implement with Django. There is a Python API that comes with the Sphinx source though.
  • The search service daemon (searchd) is pretty low on memory usage – and you can set limits on how much memory the indexer process uses too.
  • Scalability is where my knowledge is more sketchy – but it’s easy enough to copy index files to multiple machines and run several searchd daemons. The general impression I get from others though is that it’s pretty damn good under high load, so scaling it out across multiple machines isn’t something that needs to be dealt with.
  • There’s no support for ‘did-you-mean’, etc – although these can be done with other tools easily enough. Sphinx does stem words though using dictionaries, so ‘driving’ and ‘drive’ (for example) would be considered the same in searches.
  • Sphinx doesn’t allow partial index updates for field data though. The common approach to this is to maintain a delta index with all the recent changes, and re-index this after every change (and those new results appear within a second or two). Because of the small amount of data, this can take a matter of seconds. You will still need to re-index the main dataset regularly though (although how regularly depends on the volatility of your data – every day? every hour?). The fast indexing speeds keep this all pretty painless though.

I’ve no idea how applicable to your situation this is, but Evan Weaver compared a few of the common Rails search options (Sphinx, Ferret (a port of Lucene for Ruby) and Solr), running some benchmarks. Could be useful, I guess.

I’ve not plumbed the depths of MySQL’s full-text search, but I know it doesn’t compete speed-wise nor feature-wise with Sphinx, Lucene or Solr.

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