Merge pull request ClickHouse#80723 from ClickHouse/alexey-milovidov-patch-8

Update JSON.md

Author: alexey-milovidov

docs/en/interfaces/formats/JSON/JSON.md

@@ -23,7 +23,7 @@ The `JSON` format returns the following:
 | `meta`                       | Column names and types.                                                                                                                                                                                                                    |
 | `data`                       | Data tables                                                                                                                                                                                                                                |
 | `rows`                       | The total number of output rows.                                                                                                                                                                                                           |
-| `rows_before_limit_at_least` | The minimal number of rows there would have been without LIMIT. Output only if the query contains LIMIT. If the query contains `GROUP BY`, rows_before_limit_at_least is the exact number of rows there would have been without a `LIMIT`. |
+| `rows_before_limit_at_least` | The lower estimate of the number of rows there would have been without LIMIT. Output only if the query contains LIMIT. This estimate is calculated from the blocks of data processed in the query pipeline before the limit transform, but could then be discarded by the limit transform. If the blocks didn't even reach the limit transform in the query pipeline, they don't participate in the estimation. |
 | `statistics`                 | Statistics such as `elapsed`, `rows_read`, `bytes_read`.                                                                                                                                                                                   |
 | `totals`                     | Total values (when using WITH TOTALS).                                                                                                                                                                                                     |
 | `extremes`                   | Extreme values (when extremes are set to 1).                                                                                                                                                                                               |
@@ -105,4 +105,4 @@ the types from metadata in input data will be compared with the types of the cor
 ## See Also {#see-also}
 
 - [JSONEachRow](/interfaces/formats/JSONEachRow) format
-- [output_format_json_array_of_rows](/operations/settings/settings-formats.md/#output_format_json_array_of_rows) setting
+- [output_format_json_array_of_rows](/operations/settings/settings-formats.md/#output_format_json_array_of_rows) setting