Text search

Text search allows you to look up nodes and edges whose properties contain specific text. To make a node or edge searchable, you must first create a text index for it.

Text indices and search are powered by the Tantivy full-text search engine.

Create text index

Before you can use text search, you need to create a text index. Text indices are created using the CREATE TEXT INDEX command. To create the text index, you need to:

1. Provide a name for the index.
2. Specify the label or edge type the index applies to.
3. (Optional) Define which properties should be indexed.

Create a text index on nodes

CREATE TEXT INDEX text_index_name ON :Label;

Create a text index on edges

CREATE TEXT EDGE INDEX text_index_name ON :EDGE_TYPE;

Index all properties

This statement creates a text index named complianceDocuments for nodes with the Report label, indexing all text-indexable properties:

CREATE TEXT INDEX complianceDocuments ON :Report;

Index specific properties

You can also create a text index on a subset of properties by specifying them explicitly:

CREATE TEXT INDEX index_name ON :Label(prop1, prop2, prop3);

For example, to create an index only on the title and content properties of Report nodes:

CREATE TEXT INDEX complianceDocuments ON :Report(title, content);

Edge text indices

Text indices can also be created on edges. To create a text index on edges:

CREATE TEXT EDGE INDEX edge_index_name ON :EDGE_TYPE;

You can also specify specific properties for edge indices:

CREATE TEXT EDGE INDEX edge_index_name ON :EDGE_TYPE(prop1, prop2);

If you attempt to create an index with an existing name, the statement will fail.

What is indexed

For any given node or edge, if a text index applies to it:

• When no specific properties are listed, all properties with text-indexable types (String, Integer, Float, or Boolean) are stored.
• When specific properties are listed, only those properties (if they have text-indexable types) are stored.

Run text search

To run text search, you need to call text_search query module procedures.

Show text indices

To list all text indices in Memgraph, use the SHOW INDEX INFO statement.

Query text index

Use the text_search.search() and text_search.search_edges() procedures to search for text within a text index. These procedures allow you to find nodes or edges that match your search query based on their indexed properties.

Input:

• index_name: string ➡ The text index to search.
• search_query: string ➡ The query to search for in the index.
• limit: int (optional, default=1000) ➡ The maximum number of results to return.

Output:

When the index is defined on nodes:

• node: Node ➡ A node in the text index matching the given query.
• score: double ➡ The relevance score of the match. Higher scores indicate more relevant results.

When the index is defined on edges:

• edge: Relationship ➡ An edge in the text index matching the given query.
• score: double ➡ The relevance score of the match. Higher scores indicate more relevant results.

Usage:

The syntax for the search_query parameter is available here. If the query contains property names, attach the data. prefix to them.

CALL text_search.search("index_name", "data.title:Rules2024") YIELD node, score RETURN *;

To query an index on edges, use:

CALL text_search.search_edges("index_name", "data.title:Rules2024") YIELD edge, score RETURN *;

Example

CREATE TEXT INDEX complianceDocuments ON :Document; CREATE (:Document {title: 'Rules2024', version: 1}); CREATE (:Document {title: 'Rules2024', version: 2}); CREATE (:Document {title: 'Other', version: 2});   // Search for documents with title containing 'Rules2024' CALL text_search.search('complianceDocuments', 'data.title:Rules2024')  YIELD node RETURN node.title AS title, node.version AS version ORDER BY version ASC;

Result:

+-------------+-------------+ | title | version | +-------------+-------------+ | "Rules2024" | 1 | | "Rules2024" | 2 | +-------------+-------------+

Boolean expressions

You can use boolean logic in your search queries to create more complex search conditions. Boolean operators include AND, OR, and NOT, and you can use parentheses to group conditions.

Usage:

Boolean expressions allow you to combine multiple search conditions:

• AND - both conditions must be true
• OR - at least one condition must be true
• NOT - condition must be false
• Use parentheses () to group conditions and control precedence

Example

CREATE TEXT INDEX complianceDocuments ON :Document; CREATE (:Document {title: 'Rules2023', fulltext: 'nothing'}); CREATE (:Document {title: 'Rules2024', fulltext: 'words', version: 2});   // Search with boolean logic: (title is Rules2023 OR Rules2024) AND fulltext contains 'words' CALL text_search.search('complianceDocuments', '(data.title:Rules2023 OR data.title:Rules2024) AND data.fulltext:words')  YIELD node RETURN node.title AS title, node.version AS version ORDER BY version ASC, title ASC;

Result:

+-------------+-------------+ | title | version | +-------------+-------------+ | "Rules2024" | 2 | +-------------+-------------+

Search over all indexed properties

The text_search.search_all and text_search.search_all_edges procedures look for text-indexed nodes or edges where at least one property value matches the given query.

Unlike text_search.search, these procedures search over all properties, and there is no need to specify property names in the query.

Input:

• index_name: string ➡ The text index to be searched.
• search_query: string ➡ The query applied to the text-indexed nodes or edges.
• limit: int (optional, default=1000) ➡ The maximum number of results to return.

Output:

When the index is defined on nodes:

• node: Node ➡ A node in index_name matching the given search_query.
• score: double ➡ The relevance score of the match. Higher scores indicate more relevant results.

When the index is defined on edges:

• edge: Relationship ➡ An edge in index_name matching the given search_query.
• score: double ➡ The relevance score of the match. Higher scores indicate more relevant results.

Usage:

The following query searches the complianceDocuments index for nodes where at least one property value contains Rules2024:

CALL text_search.search_all("complianceDocuments", "Rules2024") YIELD node RETURN node;

To search edges:

CALL text_search.search_all_edges("complianceEdges", "Rules2024") YIELD edge RETURN edge;

Example

CREATE TEXT INDEX complianceDocuments ON :Document; CREATE (:Document {title: 'Rules2024', fulltext: 'text words', version: 1}); CREATE (:Document {title: 'Other', fulltext: 'Rules2024 here', version: 3});   // Search for 'Rules2024' across all properties CALL text_search.search_all('complianceDocuments', 'Rules2024')  YIELD node RETURN node ORDER BY node.version ASC;

Result:

+----------------------------------------------------------------------+ | node | +----------------------------------------------------------------------+ | (:Document {fulltext: "text words", title: "Rules2024", version: 1}) | | (:Document {fulltext: "Rules2024 here", title: "Other", version: 3}) | +----------------------------------------------------------------------+

Regex search

The text_search.regex_search and text_search.regex_search_edges procedures look for text-indexed nodes or edges where at least one property value matches the given regular expression (regex).

Input:

• index_name: string ➡ The text index to be searched.
• search_query: string ➡ The regex applied to the text-indexed nodes or edges.
• limit: int (optional, default=1000) ➡ The maximum number of results to return.

Output:

When the index is defined on nodes:

• node: Node ➡ A node in index_name matching the given search_query.
• score: double ➡ The relevance score of the match. Higher scores indicate more relevant results.

When the index is defined on edges:

• edge: Relationship ➡ An edge in index_name matching the given search_query.
• score: double ➡ The relevance score of the match. Higher scores indicate more relevant results.

Usage:

Regex searches apply to all properties; do not include property names in the search query.

The following query searches the complianceDocuments index for nodes where at least one property value satisfies the wor.*s regex, e.g. “works” and “words”:

CALL text_search.regex_search("complianceDocuments", "wor.*s") YIELD node RETURN node;

To search edges:

CALL text_search.regex_search_edges("complianceEdges", "wor.*s") YIELD edge RETURN edge;

Example

CREATE TEXT INDEX complianceDocuments ON :Document; CREATE (:Document {fulltext: 'words and things'}); CREATE (:Document {fulltext: 'more words'});   // Search using regex pattern 'wor.*s' CALL text_search.regex_search('complianceDocuments', 'wor.*s')  YIELD node RETURN node ORDER BY node.fulltext ASC;

Result:

+--------------------------------------------+ | node | +--------------------------------------------+ | (:Document {fulltext: "more words"}) | | (:Document {fulltext: "words and things"}) | +--------------------------------------------+

Aggregations

Aggregations allow you to perform calculations on text search results. By using them, you can efficiently summarize the results, calculate averages or totals, identify min/max values, and count indexed nodes or edges that meet specific criteria.

The text_search.aggregate and text_search.aggregate_edges procedures let you define an aggregation and apply it to the results of a search query.

Input:

• index_name: string ➡ The text index to be searched.
• search_query: string ➡ The query applied to the text-indexed nodes or edges.
• aggregation_query: string ➡ The aggregation (JSON-formatted) to be applied to the output of search_query.
• limit: int (optional, default=1000) ➡ The maximum number of results to return.

Output:

• aggregation: string ➡ JSON-formatted string with the output of aggregation.

Usage:

Aggregation queries and results are strings with Elasticsearch-compatible JSON format, where "field" corresponds to node or edge properties. If the search or aggregation queries contain property names, attach the data. prefix to them.

The following query counts all nodes in the complianceDocuments index:

CALL text_search.aggregate(  "complianceDocuments",  "data.title:Rules2024",  '{"count": {"value_count": {"field": "data.version"}}}' ) YIELD aggregation RETURN aggregation;

To aggregate edges:

CALL text_search.aggregate_edges(  "complianceEdges",  "data.title:Rules2024",  '{"count": {"value_count": {"field": "data.version"}}}' ) YIELD aggregation RETURN aggregation;

Example

CREATE TEXT INDEX complianceDocuments ON :Document; CREATE (:Document {title: 'Rules2024', version: 1}); CREATE (:Document {title: 'Rules2024', version: 2});   // Count documents matching the search query CALL text_search.aggregate(  'complianceDocuments',   'data.title:Rules2024',   '{"count":{"value_count":{"field":"data.version"}}}' )  YIELD aggregation RETURN aggregation;

Result:

+-------------------------------+ | aggregation | +-------------------------------+ | "{\"count\":{\"value\":2.0}}" | +-------------------------------+

Drop text index

Text indices are dropped with the DROP TEXT INDEX command. You need to give the name of the index to be deleted.

DROP TEXT INDEX text_index_name;

Compatibility

Text search supports most usage modalities that are available in Memgraph. Refer to the table below for an overview: