Mendix Expert Developer flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Non-persistent entity

An entity whose objects exist only in memory and are never stored in the database. It has no System attributes such as ID or CreatedDate and is discarded when the microflow ends.

Single-table inheritance

A persistent specialization of a persistent entity shares the same database table and ID space as its generalization; specialization-specific attributes become additional columns on that table.

Association storage direction

A reference association stores a foreign key on the child side. Many-to-many associations use a separate join table. Storing both directions adds an extra column and index.

Calculated attribute

A virtual, non-persistent attribute computed by an expression or microflow. It is never stored in the database and is recalculated each time the object is retrieved or displayed.

Microflow transaction settings

Synchronize commits at the end, Async returns immediately and commits, Never rolls back on error. Error handling is Rollback by default or Custom with an error handler.

Aggregate list activity

A microflow activity that computes count, sum, average, minimum, or maximum over a list without a manual loop. It is cheaper than iterating and accumulating a variable.

Nanoflow constraints

Nanoflows run client-side in the browser. They cannot call Java actions, cannot access the database directly, and cannot use server-side retrieve activities on persistent entities.

Retrieve by association

A retrieve operation that follows an association from an object to its associated objects. It is typically faster than an equivalent XPath join for one-to-many navigation.

Module role versus user role

Module roles are defined per module and grant entity, microflow, and page access. User roles are app-level and map to module roles; a user receives the union of all mapped module roles.

Entity access rule

A rule granting a module role create, read, write, or delete rights on an entity, optionally restricted by an XPath constraint and by member-level attribute access. Rules are OR-ed.

CurrentUser token

An XPath token usable in entity access constraints that resolves to the logged-in user. It restricts which objects a user can see, for example only objects they own.

Demo users

Development-only accounts configured in Project Security that bypass the configured authentication. They do not exist in production environments and cannot be used there.

Published REST operation

A REST endpoint defined on an entity or microflow with an HTTP method and path. Microflow-based operations receive path, query, and body parameters as primitives or entities.

Import mapping

A model document that maps JSON or XML elements to entity attributes, supporting by-name or by-path matching and inheritance for polymorphic structures.

Consumed web service

A SOAP integration created by importing a WSDL. It generates a service definition and is invoked with the Call web service activity using XML mappings.

REST custom authentication

A published REST authentication mode where a microflow validates credentials or an API key and returns a System.User object, or null to reject the request.

N+1 query pattern

Retrieving a list and then retrieving an associated object for each item inside a loop. It issues one query per item and is a common cause of slow microflows.

Runtime statelessness

The Mendix runtime keeps session state in the database and file storage, so horizontal scaling requires shared database and file storage plus session affinity at the load balancer.

Commit inside loop

Committing each iteration of a loop creates one database transaction per item. Committing once after the loop reduces transaction overhead substantially.

Scheduled event leader

In a multi-instance cluster only one runtime node executes a scheduled event. Long-running events on that node can delay other scheduled events on the same node.

Deployment package

An immutable build of a committed revision containing the model, custom Java, and runtime. It is promoted unchanged between environments; constants are set per environment.

Clean deploy

A deployment that wipes the environment database and file storage before starting the new package. It causes data loss and is only appropriate when that is acceptable.

Log levels

TRACE, DEBUG, INFO, WARNING, ERROR, CRITICAL. The level is configured per log node per environment, so a DEBUG message is hidden unless that node is raised.

JVM heap setting

The Xmx value for the runtime's Java virtual machine. It is set per environment and should leave headroom below the container memory limit for the OS and metaspace.

Module boundary

A module owns its entities and exposes microflows as its API. Other modules call those microflows rather than directly manipulating the owning module's entities.

Constant for configuration

A named value defined in the model and overridden per environment. It keeps URLs, keys, and environment-specific settings out of microflow logic.

Event handler placement

Before and after commit, create, and delete handlers belong in the module that owns the entity. Cross-module effects should use a microflow call or published event instead.

Mendix Unit Testing module

An App Store module that runs microflow-based test cases with assert activities and reports pass or fail per case. Tests should live in a separate test module.

Check model

A Studio Pro validation run that reports consistency errors and warnings. Errors block deployment; warnings are advisory and should be reviewed before committing.

Query log node

A log node that, at TRACE level, shows the SQL generated from XPath retrieves. It is the primary tool for diagnosing slow or unexpected database queries.

Team Server branching

A Git-based repository hosted by Mendix. Branches are created from a revision, and merge conflicts on model documents are resolved in Studio Pro's conflict dialog.

Deploy API

A Mendix API that automates deployment of a deployment package to an environment. It requires a per-environment API key and is used in CI/CD pipelines.