Performance recommendations

Specify the target database on all queries using the database parameter, both in Driver.executeQuery() calls and when creating new sessions. If no database is provided, the driver has to send an extra request to the server to figure out what the default database is. The overhead is minimal for a single session, but becomes significant over hundreds of sessions.
```
// Good practice
driver.executeQuery('<QUERY>', {}, {database: '<DB NAME>'})
driver.session({database: '<DB NAME>'})
```
```
// Bad practice
driver.executeQuery('<QUERY>')
driver.session()
```

Use query parameters instead of hardcoding or concatenating values into queries. This allows to leverage the database’s query cache.

// Good practice
driver.executeQuery(
  'MATCH (p:Person {name: $name}) RETURN p',
  { name: 'Alice' }  // query parameters
)

// Bad practice
driver.executeQuery('MATCH (p:Person {name: "Alice"}) RETURN p')
driver.executeQuery('MATCH (p:Person {name: ' + name + '}) RETURN p')

Specify node labels in all queries. To learn how to combine labels, see Cypher — Label expressions.

// Good practice
driver.executeQuery('MATCH (p:Person|Animal {name: $name}) RETURN p', { name: 'Alice' })

// Bad practice
driver.executeQuery('MATCH (p {name: $name}) RETURN p', { name: 'Alice' })

Batch queries when creating a lot of records using the WITH and UNWIND Cypher clauses.

// Good practice
numbers = []
for(let i=0; i<10000; i++) {
  numbers.push({value: Math.random()})
}
driver.executeQuery(`
    WITH $numbers AS batch
    UNWIND batch AS node
    MERGE (n:Number {value: node.value})
    `, { numbers: numbers }
)

// Bad practice
for(let i=0; i<10000; i++) {
  driver.executeQuery('MERGE (:Number {value: $value})', { value: Math.random() })
}

The most efficient way of performing a first import of large amounts of data into a new database is the neo4j-admin database import command.

Create indexes for properties that you often filter against. For example, if you often look up Person nodes by the name property, it is beneficial to create an index on Person.name. You can create indexes with the CREATE INDEX Cypher function, for both nodes and relationships. For more information, see Indexes for search performance.
```
// Create an index on Person.name
driver.executeQuery('CREATE INDEX personName FOR (n:Person) ON (n.name)')
```

Profile your queries to locate queries whose performance can be improved. You can profile queries by prepending them with PROFILE. The server output is available in the profile property of the ResultSummary object.

const result = driver.executeQuery('PROFILE MATCH (p {name: $name}) RETURN p', { name: 'Alice' })
console.log(result.summary.profile.arguments['string-representation'])

/*
Planner COST
Runtime PIPELINED
Runtime version 5.0
Batch size 128

+-----------------+----------------+----------------+------+---------+----------------+------------------------+-----------+---------------------+
| Operator        | Details        | Estimated Rows | Rows | DB Hits | Memory (Bytes) | Page Cache Hits/Misses | Time (ms) | Pipeline            |
+-----------------+----------------+----------------+------+---------+----------------+------------------------+-----------+---------------------+
| +ProduceResults | p              |              1 |    1 |       3 |                |                        |           |                     |
| |               +----------------+----------------+------+---------+----------------+                        |           |                     |
| +Filter         | p.name = $name |              1 |    1 |       4 |                |                        |           |                     |
| |               +----------------+----------------+------+---------+----------------+                        |           |                     |
| +AllNodesScan   | p              |             10 |    4 |       5 |            120 |                 9160/0 |   108.923 | Fused in Pipeline 0 |
+-----------------+----------------+----------------+------+---------+----------------+------------------------+-----------+---------------------+

Total database accesses: 12, total allocated memory: 184
*/

If your query is so slow that you are unable to even run it in a reasonable time, you can prepend it with EXPLAIN instead of PROFILE. This will return the plan that the server would use to run the query, but without executing it. The server output is available in the plan property of the ResultSummary object.

const result = driver.executeQuery('EXPLAIN MATCH (p {name: $name}) RETURN p', { name: 'Alice' })
console.log(result.summary.plan.arguments['string-representation'])

/*
Planner COST
Runtime PIPELINED
Runtime version 5.0
Batch size 128

+-----------------+----------------+----------------+---------------------+
| Operator        | Details        | Estimated Rows | Pipeline            |
+-----------------+----------------+----------------+---------------------+
| +ProduceResults | p              |              1 |                     |
| |               +----------------+----------------+                     |
| +Filter         | p.name = $name |              1 |                     |
| |               +----------------+----------------+                     |
| +AllNodesScan   | p              |             10 | Fused in Pipeline 0 |
+-----------------+----------------+----------------+---------------------+

Total database accesses: ?
*/

Use asynchronous querying. This is likely to be more impactful on performance if you parallelize complex and time-consuming queries in your application, but not so much if you run many simple ones.

Glossary

LTS: A Long Term Support release is one guaranteed to be supported for a number of years. Neo4j 4.4 is LTS, and Neo4j 5 will also have an LTS version.
Aura: Aura is Neo4j’s fully managed cloud service. It comes with both free and paid plans. Every Neo4j-backed application requires a Driver object.
Cypher: Cypher is Neo4j’s graph query language that lets you retrieve data from the graph. It is like SQL, but for graphs.
APOC: Awesome Procedures On Cypher (APOC) is a library of (many) functions that can not be easily expressed in Cypher itself.
Bolt: Bolt is the protocol used for interaction between Neo4j instances and drivers. It listens on port 7687 by default.
ACID: Atomicity, Consistency, Isolation, Durability (ACID) are properties guaranteeing that database transactions are processed reliably. An ACID-compliant DBMS ensures that the data in the database remains accurate and consistent despite failures.
eventual consistency: A database is eventually consistent if it provides the guarantee that all cluster members will, at some point in time, store the latest version of the data.
causal consistency: A database is causally consistent if read and write queries are seen by every member of the cluster in the same order. This is stronger than eventual consistency.
null: The null marker is not a type but a placeholder for absence of value. For more information, see Cypher Manual — Working with null.
transaction: A transaction is a unit of work that is either committed in its entirety or rolled back on failure. An example is a bank transfer: it involves multiple steps, but they must all succeed or be reverted, to avoid money being subtracted from one account but not added to the other.
backpressure: Backpressure is a force opposing the flow of data. It ensures that the client is not being overwhelmed by data faster than it can handle.
transaction function: A transaction function is a callback executed by an executeRead or executeWrite call. The driver automatically re-executes the callback in case of server failure.
Driver: A Driver object holds the details required to establish connections with a Neo4j database.

Was this page helpful?