Performance improvement - indexes on property values

[rsill-neo4j]

No description provided.

[jamthief]

• These come out as numbered. Should they be bullet pointed instead?
• The last point is quite hard to follow. Maybe some example cypher could help? e.g.

CREATE RANGE INDEX actor_has_birthyear FOR (a:Actor) ON (a.birthYear)
CREATE RANGE INDEX director_has_birthyear FOR (d:Director) ON (d.birthYear)

// The below MATCH can leverage one of the indexes, but not both
MATCH (p:$any(["Actor", "Director"]) { birthYear: 1983 }) RETURN p.name

Also, on the last point: it is technically the operator that does this index selection and filtering, not the planner. (I'm assuming we try to make the distinction in the docs between planning and runtime/operator phases. You tell me though!)

[jamthief]

I think this example is a bit confusing in combination with the caveat overleaf which states we can't actually use both the indexes for the MATCH. Perhaps this would be better:

CREATE RANGE INDEX actor_has_birthyear FOR (a:Actor) ON (a.birthYear);

// The below MATCH can leverage the created index and then filter for the Director label
MATCH (p:$all(["Actor", "Director"]) { birthYear: 1983 }) RETURN p.name;

[jamthief]

Or perhaps - worth checking with Matthew Wood which he prefers - a LOAD CSV example:

// people.csv
label,name,birthYear
Actor,Henry Cavill,1983

CREATE RANGE INDEX actor_has_name_and_birthyear FOR (a:Actor) ON (a.name, a.birthYear);

LOAD CSV WITH HEADERS FROM 'people.csv' AS row
// The below MERGE can leverage the index to check for existence before a CREATE
MERGE (:$(row.label) { name: row.name, birthYear: row.birthYear) })

[jamthief]

I think I like the LOAD CSV example better, if that helps!

[jamthief]

Looks great! Minor last comments, so approving proactively. 🍪

[jamthief]

Not sure why I made this more complicated than it needs to be now 😕

The point can still be illustrated with a single property index. Feel free to slim it down, or leave as is.

// people.csv
label,name
Actor,Henry Cavill

CREATE RANGE INDEX actor_has_name FOR (a:Actor) ON (a.name);

LOAD CSV WITH HEADERS FROM 'people.csv' AS row
// The MERGE below can leverage the index to check for existence before a CREATE
MERGE (:$(row.label) { name: row.name })

[neo4j-docops-agent]

This PR includes documentation updates
View the updated docs at https://neo4j-docs-cypher-1440.surge.sh

Updated pages:

• MATCH
• MERGE
• Additions, deprecations, removals, and compatibility