The standard use case for a multi-field is when a field needs to be both analyzed (for searching) and not analyzed (for aggregating/sorting). In this case, there really is no workaround, so a multi-field is essential.
In the different analyzer case, it gets more complicated. How much can you get away with with just one field? How important is query precision compared to storage? In general, more fields are needed because they are truly needed. The upcoming Elasticsearch book has a good chapter on languages, which is one use case in which multi fields are used. The pitfalls of mixing languages section is what you might encounter when attempting to use fewer fields. http://www.elasticsearch.org/guide/en/elasticsearch/guide/current/languages.html Cheers, Ivan On Wed, Aug 27, 2014 at 11:02 AM, gek8365 <glenn.k...@gmail.com> wrote: > Greetings, > > I am somewhat new to elasticsearch and I am trying to understand the > implications of multi_fields in terms of performance/memory consumption. I > see from the documents that multi_fields are useful when you want to > analyze field data in different ways. What I do not see is any discussion > on how expensive it is to have these additional "fields." I realize that > this is a very glib question, which is due in large to my ignorance, so any > advice or links to documents that might have some information on this would > be very useful and I would be grateful. Thanks in advance. > > > -- > 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 elasticsearch+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/elasticsearch/d05347a1-abf1-401e-bd48-487bb2162c32%40googlegroups.com > <https://groups.google.com/d/msgid/elasticsearch/d05347a1-abf1-401e-bd48-487bb2162c32%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- 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 elasticsearch+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/elasticsearch/CALY%3DcQCVphM-x7a1MUDgbM7zSX7Y9po7m8Ne5tguSMvz%2BtTt6g%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
