How to profile queries

Along with inspecting a query's plan as described in the Inspecting queries guide, it is also possible to profile the execution of a query and get a detailed report on how the query's plan behaved. For every logical operator the following info is provided:

• OPERATOR — the name of the operator, just like in the output of an EXPLAIN query.

• ACTUAL HITS — the number of times a particular logical operator was pulled from.

• RELATIVE TIME — the amount of time that was spent processing a particular logical operator, relative to the execution of the whole plan.

• ABSOLUTE TIME — the amount of time that was spent processing a particular logical operator.

A simple example to illustrate the output:

PROFILE MATCH (n :Node)-[:Edge]-(m :Node) WHERE n.prop = 42 RETURN *;

+---------------+---------------+---------------+---------------+
| OPERATOR      | ACTUAL HITS   | RELATIVE TIME | ABSOLUTE TIME |
+---------------+---------------+---------------+---------------+
| * Produce     | 1             |   7.134628 %  |   0.003949 ms |
| * Filter      | 1             |  12.734765 %  |   0.007049 ms |
| * Expand      | 1             |   5.181460 %  |   0.002868 ms |
| * ScanAll     | 1             |   3.325061 %  |   0.001840 ms |
| * ScanAll     | 1             |  71.061241 %  |   0.039334 ms |
| * Once        | 2             |   0.562844 %  |   0.000312 ms |
+---------------+---------------+---------------+---------------+

Where to next?

To learn more about Memgraph's functionalities, visit the Reference guide. For real-world examples of how to use Memgraph, we strongly suggest going through one of the available Tutorials.