More documentation improvements for fielddata loading.

docs/reference/index-modules/fielddata.asciidoc

@@ -92,8 +92,8 @@ field data format.
 [float]
 === Fielddata loading
 
-By default, field data is loaded lazily, on the first time that a query that
-requires field data is fired. However, this can make the first requests that
+By default, field data is loaded lazily, ie. the first time that a query that
+requires them is executed. However, this can make the first requests that
 follow a merge operation quite slow since fielddata loading is a heavy
 operation.
 
@@ -118,9 +118,9 @@ It is possible to force field data to be loaded and cached eagerly through the
 Field data can take a lot of RAM so it makes sense to disable field data
 loading on the fields that don't need field data, for example those that are
 used for full-text search only. In order to disable field data loading, just
-change the field data format to `disabled`. Request that will try to load field
-data on any field which is configured with this format will then return an
-error.
+change the field data format to `disabled`. When disabled, all requests that
+will try to load field data, e.g. when they include aggregations and/or sorting,
+will return an error.
 
 [source,js]
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