Glossary

CSI

CSI

Container Storage Interface

A standard connecting a container platform to storage. A CSI driver does not remove the need to understand durability, zones and backups.

CSRF

CSRF

Cross-Site Request Forgery

An attack exploiting automatically attached browser credentials to trigger an unwanted operation. Defences depend on session and cookie design; CORS alone is insufficient.

CSV and TSV

CSV

Comma-Separated Values

TSV

Tab-Separated Values

Text formats representing rows and delimiter-separated fields. Handle quoting, delimiter, encoding and size limits; simple split is not a correct parser.

DaemonSet

Runs Pods on selected nodes, such as a log agent. It is not arbitrary replica-based application scaling like a Deployment.

Data Definition Language

DDL

Data Definition Language

SQL commands changing database structure, such as CREATE or ALTER. A migration may block production queries; assess its operational cost.

Data Manipulation Language

DML

Data Manipulation Language

SQL commands operating on data, such as INSERT, UPDATE and DELETE. Valid syntax does not prevent data loss from an incorrect WHERE clause.

Data Mapper

Separates row/object translation from domain behaviour. Account need not execute SQL or know the ORM session.

Data schema

A description of data structure, such as tables, columns, types and constraints. Changes may need staged delivery so old and new applications coexist.

Data type

A description of values and allowed operations. Compile-time checking does not replace validation of network or file input.

Data validation

Checking input format, ranges and required fields. HTTP validation does not replace domain invariants or database constraints under concurrent writes.

Database

DB

Database

A system that stores and serves data with defined guarantees. Understand its transaction model, constraints, recovery procedures and write ownership.

Database constraint

A database-enforced rule, such as uniqueness, a foreign key or non-overlapping reservations. It also protects writes that bypass application validation.

Database index

An additional structure for locating data without scanning the whole table. Faster reads cost space and write maintenance; query plans show whether an index helps.

Database migration

A versioned schema or data change. Define ordering, execution conditions and recovery; reverting application code does not automatically undo a migration.

Daylight Saving Time

DST

Daylight Saving Time

A seasonal change of local UTC offset. A local day can have 23 or 25 hours; do not equate it with a 24-hour interval.

DDD

DDD

Domain-Driven Design

A modelling approach grounded in domain language, rules and responsibility boundaries. Naming a class Aggregate does not replace identifying real invariants and data ownership.

Deadline

The time boundary for an entire operation, including attempts, waiting and backoff. Giving each attempt a full timeout can exceed the user’s deadline.

Deadlock

A wait cycle where operations hold resources each other needs. Consistent lock ordering and aborted-transaction handling help; a longer timeout does not remove the cause.

Debugger

A tool pausing execution and exposing program state. Use it to diagnose data flow, not as a performance measurement.

Decimal context

Decimal calculation settings, including precision, rounding and responses to error signals. Python localcontext sets them for a block. Constructing Decimal from text does not guarantee that later operations never round.

Decimal numbers and minor units

Money can use decimal types or integer minor units. Define currency, scale and rounding; ordinary floating point can produce unexpected results.

Decorator

Wraps the same interface with added behaviour, such as measuring both success and failure. Wrapper order matters; language decorator syntax need not implement this pattern.

Deduplication

Recognizing repeated messages or operations. Choose durable keys and retention; in-memory deduplication does not survive process restart.

Default argument

A value used when a caller omits an argument. Python evaluates it when defining the function, so a default list can be shared. Create a fresh list after checking None; use default_factory in a dataclass.

Dependency BOM

BOM

Bill of Materials

A coordinated set of dependency versions imported into a build. It helps compatibility but does not replace tests or security-update review.

Dependency injection (DI)

DI

Dependency Injection

An object receives collaborators such as a clock or HTTP client instead of creating them internally. Tests can supply controlled implementations. A framework container is one way to wire dependencies.

Design pattern

A recurring arrangement of collaborating code addressing a specific change problem. It has applicability and cost; a class name does not prove good design.

Desired state

Declared state that a controller attempts to achieve. Storing a declaration does not mean every resource has reached it.

Development container

A described container development environment with tools and dependencies. It aids reproducibility but requires deliberate mounts, permissions and network access.

DI-container singleton

An object shared within a container-defined scope. It does not mean one instance across a cluster. Customer-specific state in it can leak between requests.