1.
In PostgreSQL, what holds all objects?
Correct Answer
C. Schema
Explanation
In PostgreSQL, a schema holds all objects. A schema is a logical container that organizes database objects such as tables, views, indexes, and functions. It provides a way to group related objects together and separate them from other objects in the database. By using schemas, it becomes easier to manage and organize the database structure, as well as to control access and permissions for different groups of users. Therefore, the correct answer is "Schema".
2.
The test is usually used for hiring...
Correct Answer
B. Software Engineers
Explanation
This test is typically used for hiring software engineers. Software engineers are professionals who specialize in designing, developing, and maintaining software systems. They have the necessary skills and knowledge to write efficient and reliable code, understand complex algorithms, and work with various programming languages and frameworks. The test likely assesses candidates' technical abilities, problem-solving skills, and understanding of software engineering principles, making it a suitable evaluation for hiring software engineers.
3.
PostgreSQL is often simplified as...
Correct Answer
C. Postgres
Explanation
PostgreSQL is often simplified as "Postgres". This is a common abbreviation used to refer to the open-source relational database management system. It is derived from the original name "PostgresSQL" and is widely recognized and used within the PostgreSQL community and among developers and users of the database.
4.
What kind of language allows developers to extend the database with custom functions?
Correct Answer
B. Procedural
Explanation
Procedural language allows developers to extend the database with custom functions. In procedural programming, developers can define their own functions and procedures that can be used to manipulate and process data within the database. This allows for greater flexibility and customization in database operations.
5.
Functions invoked upon modification of certain data are referred to as...
Correct Answer
C. Triggers
Explanation
Triggers are functions that are automatically executed when certain data is modified. They are used to enforce business rules, perform calculations, or update other data in response to changes in the database. Triggers can be defined to execute before or after an insert, update, or delete operation on a table. They are commonly used in database management systems to maintain data integrity and automate tasks.
6.
What languages are sandboxed and can be used by any user?
Correct Answer
C. Safe
Explanation
The correct answer is "Safe". This suggests that the languages that are sandboxed and can be used by any user are considered safe. This implies that these languages have built-in security measures that prevent malicious code from causing harm to the system or other users. By being sandboxed, these languages are isolated from the rest of the system, limiting their access and potential impact. Therefore, users can confidently use these safe languages without worrying about compromising their security or the system's integrity.
7.
Procedures written in unsafe languages can only be created by...
Correct Answer
D. Superusers
Explanation
Superusers are individuals with advanced privileges and permissions in a computer system. They have the authority to perform tasks that regular users cannot, such as creating procedures in unsafe languages. Writers, developers, and coders may have different levels of access and expertise, but it is the superusers who possess the necessary permissions to create procedures in unsafe languages.
8.
Which of these can be attached to tables?
Correct Answer
A. Triggers
Explanation
Triggers can be attached to tables in a database. Triggers are special types of stored procedures that are automatically executed in response to specific events or actions performed on the table. They are used to enforce business rules, maintain data integrity, and automate certain tasks. By attaching triggers to tables, developers can ensure that certain actions or conditions are met before allowing changes to be made to the table's data.
9.
Which of these allow the query tree of an incoming query to be rewritten?
Correct Answer
B. Rules
Explanation
Rules allow the query tree of an incoming query to be rewritten. Rules are a feature in databases that allow users to define conditions and actions to be taken when those conditions are met. In the context of query rewriting, rules can be used to modify or transform the query tree, allowing for more efficient or optimized execution plans. By defining rules, users can specify how queries should be rewritten or modified before being executed, providing flexibility and control over the query execution process.
10.
Embedded SQL is implemented using...
Correct Answer
C. Preprocessor
Explanation
Embedded SQL is implemented using a preprocessor. A preprocessor is a software tool that processes the source code before it is compiled or interpreted. In the case of embedded SQL, the preprocessor scans the source code and identifies SQL statements embedded within it. It then converts these SQL statements into calls to the appropriate database management system (DBMS) using the DBMS-specific API. This allows the source code to contain both SQL and host programming language statements, making it easier to interact with the database within the application code.