Hi Luca, Thanks for replies. In fact, I am not familiar with the internal algorithm of ElasticSearch. Seems I need to catch up these knowledge, such as lucene. Thanks a lot for clearance of this question.
Ivan Luca Cavanna於 2014年2月6日星期四UTC+8下午8時14分22秒寫道： > > How do you find the documents you need to update? I guess by executing a > query? In that case, the search won't scan all the documents, this is the > whole point of elasticsearch and lucene. There is an inverted index which > makes it easy to find matches based on the terms in your queries. > > Still, updating a lot of documents can be quite expensive, but the problem > is not exactly the query part (aka finding the documents to update) but the > update itself, as it need to get each document back, delete it and reindex > it internally (that's how updates work in lucene). This is why the update > by query feature has not been exposed yet. > > On Thursday, February 6, 2014 12:25:54 PM UTC+1, Ivan Ji wrote: >> >> Hi all, >> >> Assume I already had lot of documents inside ES and each document >> represent one file. >> >> But now I want to update some files' fields, so I need to find the >> document, get its id, and then apply the _update operation. >> >> And If I have n document to do such things and there are m document >> inside the ES, the performance to search the desired document to get its id >> is O(n*m), right? Because each finding operation needs to scan entire >> documents inside the index, does it exist any way to find the desired >> document with unique key, return immediately when found it? >> >> If so, it's really not a good option when to update a document's field. I >> am wondering what's the suggested workflow to update some file without >> knowing its id first. >> >> Ideas? >> >> Cheers, >> >> Ivan >> > -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/elasticsearch/11a76615-9f8b-4914-8623-30e050dfcce1%40googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
