diff --git a/docs/reference/scripting/fields.asciidoc b/docs/reference/scripting/fields.asciidoc index 6308fcdf623e17..ce2ab4e8504a71 100644 --- a/docs/reference/scripting/fields.asciidoc +++ b/docs/reference/scripting/fields.asciidoc @@ -26,8 +26,10 @@ Depending on how many documents you have, this could mean millions or billions of executions: these scripts need to be fast! Field values can be accessed from a script using -<>, or -<>, which are explained below. +<>, +<>, or +<>, +each of which is explained below. [[scripting-score]] [float] @@ -137,32 +139,27 @@ access `text` fields from scripts. =================================================== [float] -[[modules-scripting-stored]] -=== Stored fields and `_source` - -_Stored fields_ -- fields explicitly marked as -<> -- can be accessed using the -`_fields['field_name'].value` or `_fields['field_name']` syntax. +[[modules-scripting-source]] +=== The document `_source` -The document <>, which is really just a -special stored field, can be accessed using the `_source.field_name` syntax. -The `_source` is loaded as a map-of-maps, so properties within object fields -can be accessed as, for example, `_source.name.first`. +The document <> can be accessed using the +`_source.field_name` syntax. The `_source` is loaded as a map-of-maps, so +properties within object fields can be accessed as, for example, +`_source.name.first`. [IMPORTANT] -.Prefer doc-values to stored fields +.Prefer doc-values to _source ========================================================= -Stored fields (which includes the stored `_source` field) are much slower than -doc-values. They are optimised for returning several fields per result, -while doc values are optimised for accessing the value of a specific field in -many documents. +Accessing the `_source` field is much slower than using doc-values. The +_source field is optimised for returning several fields per result, while doc +values are optimised for accessing the value of a specific field in many +documents. - -It makes sense to use `_source` or stored fields when generating a -<> for the top ten hits from a search -result but, for other search and aggregation use cases, always prefer using -doc values. +It makes sense to use `_source` when generating a +<> for the top ten hits from a +search result but, for other search and aggregation use cases, always prefer +using doc values. ========================================================= @@ -174,16 +171,11 @@ PUT my_index { "mappings": { "properties": { - "title": { <1> - "type": "text" - }, "first_name": { "type": "text", - "store": true }, "last_name": { "type": "text", - "store": true } } } @@ -191,7 +183,6 @@ PUT my_index PUT my_index/_doc/1?refresh { - "title": "Mr", "first_name": "Barry", "last_name": "White" } @@ -199,25 +190,39 @@ PUT my_index/_doc/1?refresh GET my_index/_search { "script_fields": { - "source": { + "full_name": { "script": { "lang": "painless", - "source": "params._source.title + ' ' + params._source.first_name + ' ' + params._source.last_name" <2> + "source": "params._source.first_name + ' ' + params._source.last_name" } - }, - "stored_fields": { + } + } +} +------------------------------- + +[float] +[[modules-scripting-stored]] +=== Stored fields + +_Stored fields_ -- fields explicitly marked as +<> in the mapping -- can be accessed using the +`_fields['field_name'].value` or `_fields['field_name']` syntax: + +[source,console] +------------------------------- +GET my_index/_search +{ + "script_fields": { + "name_with_title": { "script": { "lang": "painless", - "source": "params._fields['first_name'].value + ' ' + params._fields['last_name'].value" + "source": "params._fields['name'].value + ', ' + params._fields['title'].value" } } } } ------------------------------- -<1> The `title` field is not stored and so cannot be used with the `_fields[]` syntax. -<2> The `title` field can still be accessed from the `_source`. - [TIP] .Stored vs `_source` =======================================================