Autosuggest/Autocomplete: What are the best practices to build Suggester?

[Michael Wechner]

Hi

I recently started to use the Autosuggest/Autocomplete package as 
suggested by Robert

https://www.mail-archive.com/java-user@lucene.apache.org/msg51403.html

which works very fine, thanks again for your help :-)

But it is not clear to me what are the best practices building a 
suggester using an InputIterator

https://lucene.apache.org/core/8_10_1/suggest/org/apache/lucene/search/suggest/Lookup.html#build-org.apache.lucene.search.suggest.InputIterator-

regarding

- scalability
- thousands of terms
- thousands of contexts (including personalized contexts)
- updating during runtime (singleton / thread safe)

So far I do something as follows

entities.add(new Item("traffic 
accident","",asList("public","a84581a3-302f-4b73-80d9-0e60da5238f9"),3) );
entities.add(new 
Item("event","",asList("public","a84581a3-302f-4b73-80d9-0e60da5238f9"),2));
entities.add(new 
Item("person","",asList("public","a84581a3-302f-4b73-80d9-0e60da5238f9"),4));
entities.add(new Item("coverage 
check","",asList("a84581a3-302f-4b73-80d9-0e60da5238f9"),1));
entities.add(new 
Item("coverage","",asList("a84581a3-302f-4b73-80d9-0e60da5238f9"),1));
entities.add(new Item("contract 
search","",asList("a84581a3-302f-4b73-80d9-0e60da5238f9"),1));
entities.add(new Item("claims management 
system","",asList("a84581a3-302f-4b73-80d9-0e60da5238f9"),1));

suggester.build(new ItemIterator(entities.iterator()));

whereas the terms associated with the context "public" are intended for 
all contexts and the terms associated with the context 
"a84581a3-302f-4b73-80d9-0e60da5238f9" are only for a private domain 
context, in this example an insurance company.

Let's assume we have thousands of private domain contexts and the terms 
keep changing continuously, because people upload new documents with new 
terms into these contexts.

Will the current implementation of building the suggester using 
InputIterator scale for such a situation?

I assumed/expected actually that the suggester is implemented like an 
IndexReader/DirectoryReader for searching, which means for each context 
I could have a separate "SuggesterDirectory", which can be updated 
during runtime and scales easily.

Or do I misunderstand the current concept of how to build a suggester?

Thanks

Michael