Database Reference
In-Depth Information
° Someone that intimately knows the structure, size, and semantics
of the dataset being queried in order for the imperative path to
the result set to be optimally formed
Both assumptions seem to be quite far-fetched and for this reason, many
database systems have settled on declarative approaches to querying
their data.
Structured Query Language
(
SQL
) is of course the most
well known example.
•
Expressive
: Many people have highlighted that the Cypher syntax is a
little bit like ASCII art, and it probably is. With its rounded and square
brackets, and the arrows connecting the parts of the pattern, it is very easy
to understand how the query language expresses what you are looking for.
The reason behind optimizing the syntax for reading is simple and clear:
most code gets read far more often than that it gets written. Expressiveness,
therefore, is a very interesting attribute for teams working together on a
system that relies on the Neo4j graph Database Management System.
•
Pattern
Matching
: Cypher is a pattern matching query language. This is
probably one of the more "graphy" aspects of the language, as it allows
people to sketch and draw complex relationships between different entities
in the data set quite easily. Humans are actually very good at working with
patterns; it tends to be very easy for our brain to work with them. Many
people therefore experience cypher as a very easy query language to get
started with.
•
Idempotent
: When Neo Technology started working on Cypher, the lead
architect of the query language, Andres Taylor, set out to do so using Scala,
a functional programming language on the Java Virtual Machine. One of the
key traits of functional programing environments is that they are supposed
to be idempotent. In layman's terms, this means that when you operate a
function (or in our case, execute a query) in your algorithm, changes in the
datashouldonlyhappenontheirstexecutionofthefunction.Multiple
executions of the same function over the same data should have no effect.
This has some great advantages in functional programs, but also in the
Neo4j database, as state change will be expressed idempotently.
Knowing this, we can now explore some of the key operative words in Cypher,
and familiarize you with some of these concepts in the real world.
