Commercial Databases

These question-and-answer flashcards review the key characteristics, strengths, and limitations of SQLite, SQL Server, Oracle, MySQL, MariaDB, and PostgreSQL, along with fundamental DBMS concepts such as ACID compliance and concurrency.

What is the primary purpose of a Database Management System (DBMS)?

To organize, store, retrieve, and manipulate data in a structured way.

Name the six DBMS products covered in this lesson.

SQLite, SQL Server, Oracle, MySQL, MariaDB, and PostgreSQL.

Which DBMS is serverless and accesses the database file directly without a separate server process?

SQLite.

What important ACID property does SQLite guarantee even during a crash or power outage?

All four ACID properties—Atomicity, Consistency, Isolation, Durability—are maintained.

What is a major limitation of SQLite regarding simultaneous data changes?

Limited concurrency: only one process can write to the database at a time.

Why can’t user‐level permissions be set within SQLite itself?

SQLite relies on the operating system’s file permissions; it has no built-in user permission system.

Which Microsoft DBMS offers editions ranging from Express to Enterprise and supports Transact-SQL?

SQL Server.

Approximately how much can a single SQL Server Enterprise edition license cost per core?

Upwards of $14,000 per core.

Unlike Microsoft Access, SQL Server can run on which two additional environments?

Linux and cloud environments.

Which DBMS is known for PL/SQL, a procedural language for grouping procedures and functions into packages?

Oracle.

What is the free Oracle edition intended primarily for training purposes called?

Oracle XE (Express Edition).

Why did the original MySQL developers create MariaDB?

They feared Oracle would discontinue or restrict MySQL after acquiring it.

What distinguishes MariaDB Enterprise from MariaDB Community?

MariaDB Enterprise is a commercial service offering support and extra features, while the software itself remains open source.

Give two major websites that rely on MySQL for their databases.

Twitter and YouTube (others include Facebook, Airbnb, Netflix).

Which open-source DBMS is praised for high standards compliance and extensibility, including object-relational features like table inheritance?

PostgreSQL.

Why is PostgreSQL considered easier to migrate across operating systems compared to some other DBMSs?

It is compatible with many programming languages and platforms, aiding cross-platform portability.

What major drawback limits PostgreSQL’s adoption compared with MySQL?

Fewer third-party tools are available for PostgreSQL.

Define "Concurrency" in database contexts.

The ability for multiple users or processes to access and change a file simultaneously.

Which two DBMSs discussed have strictly commercial licensing with no open-source core?

SQL Server and Oracle (although Oracle offers a free XE edition for training).

When evaluating which DBMS to use, list four common decision factors highlighted in the lesson.

Features, performance, scalability, and cost.