docs: sync Haystack API reference on Docusaurus

docs-website/reference/haystack-api/document_stores_api.md

@@ -105,7 +105,7 @@ Deserializes the component from a dictionary.
 save_to_disk(path: str) -> None
 ```
 
-Write the database and its' data to disk as a JSON file.
+Write the database and its data to disk as a JSON file.
 
 **Parameters:**
 
@@ -117,7 +117,7 @@ Write the database and its' data to disk as a JSON file.
 load_from_disk(path: str) -> InMemoryDocumentStore
 ```
 
-Load the database and its' data from disk as a JSON file.
+Load the database and its data from disk as a JSON file.
 
 **Parameters:**
 
@@ -133,7 +133,7 @@ Load the database and its' data from disk as a JSON file.
 count_documents() -> int
 ```
 
-Returns the number of how many documents are present in the DocumentStore.
+Returns the number of documents present in the DocumentStore.
 
 #### filter_documents
 
@@ -143,12 +143,10 @@ filter_documents(filters: dict[str, Any] | None = None) -> list[Document]
 
 Returns the documents that match the filters provided.
 
-For a detailed specification of the filters, refer to the DocumentStore.filter_documents() protocol
-documentation.
-
 **Parameters:**
 
-- **filters** (<code>dict\[str, Any\] | None</code>) – The filters to apply to the document list.
+- **filters** (<code>dict\[str, Any\] | None</code>) – The filters to apply. For a detailed specification of the filters, refer to the
+  [documentation](https://docs.haystack.deepset.ai/docs/metadata-filtering).
 
 **Returns:**
 
@@ -176,7 +174,7 @@ Deletes all documents with matching document_ids from the DocumentStore.
 
 **Parameters:**
 
-- **document_ids** (<code>list\[str\]</code>) – The object_ids to delete.
+- **document_ids** (<code>list\[str\]</code>) – The document_ids to delete.
 
 #### delete_all_documents
 
@@ -229,6 +227,98 @@ Deletes all documents that match the provided filters.
 
 - <code>ValueError</code> – if filters have invalid syntax.
 
+#### count_documents_by_filter
+
+```python
+count_documents_by_filter(filters: dict[str, Any]) -> int
+```
+
+Returns the number of documents that match the provided filters.
+
+**Parameters:**
+
+- **filters** (<code>dict\[str, Any\]</code>) – The filters to apply.
+  For a detailed specification of the filters, refer to the
+  [documentation](https://docs.haystack.deepset.ai/docs/metadata-filtering).
+
+**Returns:**
+
+- <code>int</code> – The number of documents that match the filters.
+
+#### count_unique_metadata_by_filter
+
+```python
+count_unique_metadata_by_filter(
+    filters: dict[str, Any], metadata_fields: list[str]
+) -> dict[str, int]
+```
+
+Returns the number of unique values for each specified metadata field from documents matching the filters.
+
+**Parameters:**
+
+- **filters** (<code>dict\[str, Any\]</code>) – The filters to apply.
+  For a detailed specification of the filters, refer to the
+  [documentation](https://docs.haystack.deepset.ai/docs/metadata-filtering).
+- **metadata_fields** (<code>list\[str\]</code>) – List of field names to count unique values for.
+  Field names can include or omit the "meta." prefix.
+
+**Returns:**
+
+- <code>dict\[str, int\]</code> – A dictionary mapping each metadata field name (without "meta." prefix)
+  to the count of its unique values among the filtered documents.
+
+#### get_metadata_fields_info
+
+```python
+get_metadata_fields_info() -> dict[str, dict[str, str]]
+```
+
+Returns information about the metadata fields present in the stored documents.
+
+Types are inferred from the stored values (keyword, int, float, boolean).
+
+**Returns:**
+
+- <code>dict\[str, dict\[str, str\]\]</code> – A dictionary mapping each metadata field name to a dict with a "type" key.
+
+#### get_metadata_field_min_max
+
+```python
+get_metadata_field_min_max(metadata_field: str) -> dict[str, Any]
+```
+
+Returns the minimum and maximum values for the given metadata field across all documents.
+
+**Parameters:**
+
+- **metadata_field** (<code>str</code>) – The metadata field name. Can include or omit the "meta." prefix.
+
+**Returns:**
+
+- <code>dict\[str, Any\]</code> – A dictionary with "min" and "max" keys. Returns `{"min": None, "max": None}`
+  if the field is missing or has no values.
+
+#### get_metadata_field_unique_values
+
+```python
+get_metadata_field_unique_values(
+    metadata_field: str, search_term: str | None = None
+) -> tuple[list[str], int]
+```
+
+Returns unique values for a metadata field, optionally filtered by a search term in content.
+
+**Parameters:**
+
+- **metadata_field** (<code>str</code>) – The metadata field name. Can include or omit the "meta." prefix.
+- **search_term** (<code>str | None</code>) – If set, only documents whose content contains this term (case-insensitive)
+  are considered.
+
+**Returns:**
+
+- <code>tuple\[list\[str\], int\]</code> – A tuple of (list of unique values, total count of unique values).
+
 #### bm25_retrieval
 
 ```python
@@ -291,7 +381,7 @@ Retrieves documents that are most similar to the query embedding using a vector
 count_documents_async() -> int
 ```
 
-Returns the number of how many documents are present in the DocumentStore.
+Returns the number of documents present in the DocumentStore.
 
 #### filter_documents_async
 
@@ -301,12 +391,10 @@ filter_documents_async(filters: dict[str, Any] | None = None) -> list[Document]
 
 Returns the documents that match the filters provided.
 
-For a detailed specification of the filters, refer to the DocumentStore.filter_documents() protocol
-documentation.
-
 **Parameters:**
 
-- **filters** (<code>dict\[str, Any\] | None</code>) – The filters to apply to the document list.
+- **filters** (<code>dict\[str, Any\] | None</code>) – The filters to apply. For a detailed specification of the filters, refer to the
+  [documentation](https://docs.haystack.deepset.ai/docs/metadata-filtering).
 
 **Returns:**
 
@@ -334,7 +422,7 @@ Deletes all documents with matching document_ids from the DocumentStore.
 
 **Parameters:**
 
-- **document_ids** (<code>list\[str\]</code>) – The object_ids to delete.
+- **document_ids** (<code>list\[str\]</code>) – The document_ids to delete.
 
 #### bm25_retrieval_async