In this post you can find Complete and recently updated Correct Question and answers of PostgreSQL. All Answers updated regularly with new questions. Upwork PostgreSQL test answers of 2016.
Question:* PostgreSQL can be used from just about any major programming language, including C, C++, Perl, Python, Java, Tcl, and PHP.
Answer: • True
Question:* The value NULL, in database terminology, means?
Answer: • All of these
Question:* Tablespaces:
Answer: • Allow an administrator to designate specific locations in a file system where database objects can be stored.
Question:* A VACUUM operation is used:
Answer: • All of these
Question:* When you want to use a join between columns that are in the same table, you use what type of join?
Answer: • self
Question:* True or False? ALTER TABLE may be issued while a VACUUM process is running.
Answer: • False
Question:* True or False? When using a SELECT statement on a table, or group of tables, those resources are locked exclusively.
Answer: • False
Question:* True or false: With table inheritance, not null and check constraints are inherited.
Answer: • True
Question:* If you don’t specify ASC or DESC, PostgreSQL will assume you want to see results:
Answer: • in ascending order
Question:* Deadlocks occur when:
Answer: • Two transactions hold exclusive locks on resources they both need.
Question:* True or False? VACUUM FULL shrinks indexes, optimizing database performance.
Answer: • True - This was addressed in version 9.0
Question:* WAL stands for:
Answer: • Write Ahead Log
Question:* Which of the following best describes a role:
Answer: • A template for authorization to various database objects.
Question:* What do you call the application that makes requests of the PostgreSQL server?
Answer: • Client
Question:* The basic psql command to list tables is?
Answer: • \dt
Question:* In PostgreSQL, a named collection of tables is called what?
Answer: • Schema
Question:* What command tells PostgreSQL that all of the changes you made to a database should become permanent?
Answer: • Commit
Question:* What is the wrapper around the SQL command CREATE DATABASE?
Answer: • createdb
Question:* ____________ allow us to define formally in the database how different tables relate to each other.
Answer: • Foreign Key Constraints
Question:* The SQL condition for pattern matching is?
Answer: • LIKE
Question:* The most common method to get data into a table is to use what command?
Answer: • Insert
Question:* PostgreSQL is:
Answer: • An open-source ORDBMS developed at UC Berkley, which supports many modern features.
Question:* PostgreSQL is
Answer: • a relational database management system.
Question:* With PostgreSQL, you can access data by
Answer: • All of these
Question:* When retrieving data in a particular table, we use the_____________ statement.
Answer: • SELECT FROM
Question:* The heart of SQL is the __________ statement.
Answer: • SELECT
Question:* We add data to PostgreSQL by using which statement?
Answer: • INSERT
Question:* PostgreSQL has many modern features including:
Answer: • All of the above
Question:* PostgreSQL used what model of communication?
Answer: • Client/Server
Question:* PostgreSQL runs on:
Answer: • all major operating systems, including Linux, UNIX (AIX, BSD, HP-UX, SGI IRIX, Mac OS X, Solaris, Tru64), and Windows.
Question:* PostgreSQL can be installed?
Answer: • All of these
Question:* Triggers can be configured to execute when which of the following operations are performed:
Answer: • All of the above
Question:* True or False? Within a table, a single column may be encrypted.
Answer: • True
Question:* The core PostgreSQL source code includes what interfaces?
Answer: • The C and embedded C interfaces
Question:* True or False? PostgreSQL is so lightweight that performance and reliability are not affected by hardware.
Answer: • False
Question:* True or False: A tablespace is the place where database objects are stored on disk.
Answer: • True
Question:* Unless you specify NOT NULL, PostgreSQL will assume that a column is:
Answer: • Optional
Question:* Query trees can be viewed in the server logs as long as which of the following configuration parameters are enabled?
Answer: • All of these
Question:* To create a database in PostgreSQL, you must have the special CREATEDB privilege or
Answer: • be a superuser.
Question:* A meta-command always begins with what?
Answer: • Backslash character (\)
Question:* To describe a table in PostgreSQL which of the following is correct:
Answer: • psql> \d table_name
Question:* What does the following statement do? CREATE INDEX lower_title_idx ON books ((lower(title)));
Answer: • Creates an index for efficient case-insensitive searches on the titles column within the books table
Question:* What command allows you to edit PostgreSQL queries in your favorite editor ?
Answer: • \e
Question:* To prevent transaction wraparound, a VACUUM operation should be run on every table no less than once every:
Answer: • 2 billion transactions
Question:* The rule system:
Answer: • All of these
Question:* Asynchronous Commits:
Answer: • All of these
Question:* This is used to determine how text is stored and sorted within PostgreSQL?
Answer: • Collations
Question:* What command turns on timing?
Answer: • \timing
Question:* When looking at 'ps' output on a unix system, you see the following: postgres 1016 0.1 2.4 6532 3080 pts/1 SN 13:19 0:00 postgres: tgl regression [local] idle in transaction What does "idle in transaction" mean?
Answer: • A client is connected, and the server is awaiting input.
Question:* True or False? Only the administrator can make use of tablespaces.
Answer: • False
Question:* Advisory locks are allocated out of a shared memory pool whose size is defined by the configuration variables....
Answer: • All of these
Question:* What does MCV stand for?
Answer: • Most Common Values
Question:* In order to echo all input from script, you use the ________ psql command.
Answer: • -a
Question:* Which is NOT true of array indexes?
Answer: • By default PostgreSQL indexes arrays so that inner elements can be searched.
Question:* Which statement is true about PostgreSQL data types?
Answer: • There is a non-standard PostgreSQL data type, called Geometric data type, which handles 2-dimensional data.
Question:* True or False? Dynamic Tracing is enabled by default at compile time.
Answer: • False
Question:* What is "index bloat"?
Answer: • No-longer-needed keys in an index aren't reclaimed, therefore increasing space required to store an index, as well as time it takes to scan.
Question:* To copy a database from server1 to server2, you might use which of the following:
Answer: • pg_dump -h server1 database | psql -h server2 database
Question:* To restore a PostgreSQL backup created with pg_dump, the following may be used:
Answer: • $ psql -f database_dump.psql database_name
Question:* What is the difference between DO 'some code...' and EXECUTE 'some code...' statements?
Answer: • DO lets you execute some plPgSql code without saving it to database and EXECUTE lets you execute DDL or DML only
Question:* By default, in what subdirectory of the database data directory are WAL logs contained?
Answer: • pg_xlog
Question:* The syntax to view the indexes of an existing postgreSQL table is:
Answer: • # \d table_name
Question:* Bob works for StegaCorp. His workstation's IP address is 10.5.34.8. He needs access to a database called "partners" directly from his workstation. Which of the following is the correct entry in pg_hba.conf?
Answer: • host partners bob 10.5.34.8/32 krb5
Question:* True or False? PostgreSQL supports Index Only Scans.
Answer: • True
Question:* Which of the following is not a valid integer array?
Answer: • '{1,3,4,5,{6,7}}'
Question:* What are the join strategies available to the postgreSQL planner when a SELECT query contains two or more relations?
Answer: • Nested Loop Join, Merge Join, Hash Join
Question:* Locks are recorded in:
Answer: • pg_locks system view
Question:* True or False? To increase server performance, automated CHECKPOINT operations should be setup in cron or Task Scheduler.
Answer: • False
Question:* Which of the following is NOT a feature of user defined functions?
Answer: • They can initiate subtransactions
Question:* The extension used for data encryption/decryption within PostgreSQL is:
Answer: • pgcrypto
Question:* Which statement is not true about a PostgreSQL domain?
Answer: • Domain is a namespace existing between databases and objects such as tables.
Question:* True or False? When restoring a database backed up with pg_dump, it's generally a good idea to enable WAL.
Answer: • False
Question:* True or false: When a table is created which uses a table name as a column type, not null constraints on the column type's table definition are honored by the including table.
Answer: • False
Question:* To create a database that supports UTF-8, the following command can be used:
Answer: • createdb -E UTF8 -O user database_name
Question:* True or false? Hash indexes are not crash-safe
Answer: • False
Question:* True or False: PostgreSQL allows you to implement table inheritance. This should be defined with the special keyword INHERITIS in the table design.
Answer: • False
Question:* WAL segment size is determined:
Answer: • By the configure script at compile time
Question:* What is a TOAST file?
Answer: • A file containing values too wide to fit comfortably in the main table
Question:* The __________ database model has the advantage of being able to quickly discover all of the records of one type that are related to a specific record of another type by following the pointers from the starting record.
Answer: • network
Question:* When identifying rows uniquely, we use__________keys.
Answer: • surrogate
Question:* True or false: With table inheritance child tables inherit primary and foreign key definitions from their parents
Answer: • False
Question:* True or False? To enable continuous archiving, all you have to do is set archive_mode to 'on' in postgresql.conf
Answer: • False
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