> neither ElasticSearch nor Postgres cope very well when you start mixing multiple languages in the same document.
I've done okay with that with Solr -- but it's a hard problem. If you really want to meet the needs of fluent speakers of all languages. You can do kind of sort okay in Solr trying a multi-lingual unicode-aware analysis, but to do really good you probably need separate indexed fields (with different analysis) for each language, and may need code to try to guess which passages are in which language.
It's a hard problem, but I suspect Solr gives you more flexibility than ElasticSearch to try and work out a solution (in some cases having to write some Java). Although it doesn't come with an out-of-the-box best-practice solution (I don't think there are enough solr devs who have this use case day to day; solr dev is definitely driven by it's core devs business cases).
I've done okay with that with Solr -- but it's a hard problem. If you really want to meet the needs of fluent speakers of all languages. You can do kind of sort okay in Solr trying a multi-lingual unicode-aware analysis, but to do really good you probably need separate indexed fields (with different analysis) for each language, and may need code to try to guess which passages are in which language.
It's a hard problem, but I suspect Solr gives you more flexibility than ElasticSearch to try and work out a solution (in some cases having to write some Java). Although it doesn't come with an out-of-the-box best-practice solution (I don't think there are enough solr devs who have this use case day to day; solr dev is definitely driven by it's core devs business cases).