Filter vs query

[Ismet (Ismet Glumcevic)]

Hi, can we use only filter without query and can we use query string with wildcard in filter. What are benefits of using only filter and using query string + filter? There is example of using only filter. Is this code ok?

query: {
          bool: {
            filter: [
              {
                term: { type: passedType },
              },
              {
                range: {
                  mag: {
                    gte: passedMag,
                  },
                },
              },
              {
                match: { place: passedLocation },
              }
            ],
          },
        },

[dadoonet (David Pilato)]

A query participate to the score (how much the query matches the document) where a filter just "filters" the document without computing any score.

With queries, you can sort by the most relevant documents (default behavior).
With filters, you can just say that a document matches or not.

A filter can be cached. A query can not.

@Ismet

query string with wildcard

That sounds like a bad idea...

Be aware that wildcard queries can use an enormous amount of memory and perform very badly — just think how many terms need to be queried to match the query string "a* b* c*" .