Postgres Quiz Archive

You have 200 seconds to answer 20 Random questions so think fast!

You will need to score 80% or over to pass!

Created by

Paul Sammy

PostgreSQL 14 Internals Chapter 1

A quiz to test the knowledge of those reading and learning from Postgres 14 Internals book by Egor Rogov, covering topics in Chapter 1.

1 / 20

Each tablespaces can only be assigned for use by one database

True

False

2 / 20

When PostgreSQL is running what can it be referred to as?

Choose 2 option

Instance

Postgres Server

Aurora

Quorum

3 / 20

What is the purpose of the template0 database?

Useful for Postgres support Services to debug issues

Useful for restoring data from a logical backup or creating a database with a different encoding

Useful for creating development schemas

No such database

4 / 20

It is the postmasters job to listener for incoming connections?

False

True

5 / 20

What is the purpose of the postgres database?

a template for all the other database

No such database

restoring data from a logical backup or creating a database with a different encoding

regular database that you can use at your discretion

6 / 20

Users should not modify the template0 database

True

False

7 / 20

Postgres by default has built in connection pooling abilities?

False

True

8 / 20

Each Database has its own System Catalog?

False

True

9 / 20

What command is used to create the Postgres cluster?

StartNewPG

CreateCluster

CreatePGC

Initialize

10 / 20

Which fork keeps track of available space within pages?

wal space map

vacuum space map

free space map

used space map

11 / 20

Postgres uses a thread based process model?

True

False

12 / 20

The default Page size is 2k?

False

True

13 / 20

A Postgres cluster consists of 2 or more physical servers accessing one Postgres Instance?

True

False

14 / 20

Tablespaces are used to define physical data layout?

False

True

15 / 20

The pg_default tablespace should never be used to create user tables?

False

True

16 / 20

System Catalog tables begin with which prefix?

cat_

pg_

sys_

dba_

17 / 20

How does Postgres know which schema to use if not specified?

Schema Path

Search Path

Access Path

Directory Path

18 / 20

A schema can belong to more than one database?

True

False

19 / 20

What is the purpose of wal writer?

flushes dirty pages to disk.

executes checkpoints

collects usage statistics for the instance.

writes WAL entries to disk

20 / 20

The information_schema schema provides information on Postgres release notes?

False

True

Your score is

Created by

Paul Sammy

PostgreSQL 14 Internals Chapter 2

A quiz to test the knowledge of those reading and learning from Postgres 14 Internals book by Egor Rogov, covering topics in Chapter 2.

1 / 10

At any moment the database system can contain several versions of one and the same row?

True

False

2 / 10

Which parameters sets the database default isolation level?

active_transaction_isolation

transaction_isolation_level

default_isolation_level

default_transaction_isolation

3 / 10

The SQL standard specifies three isolation levels?

False

True

4 / 10

non-repeatable read anomaly occurs when?

A transaction reads one and the same row twice, another transaction modifies this row between these reads and commits the change.

A transaction reads one and the same row twice, another transaction modifies this row between these reads issue a rollback.

A transaction reads one and the same row once and modifies this row and commits the change.

A transaction reads one and the same row once, another transaction modifies this row between these reads and commits the change.

5 / 10

Which isolation level in theory could mean an application does not have to consider isolation anomalies?

Repeatable Read

Read Committed

Read Uncommitted

Serializable

6 / 10

which of the below statements will start a transaction as Read Repeatable?

ALTER SYSTEM SET ISO=REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

7 / 10

The more locks a transaction acquires, the better it is isolated from other transactions?

False

True

8 / 10

Data Consistency is best handled at the application layer rather than at the database layer?

True

False

9 / 10

Snapshot isolation is preferred but increases the number of required locks?

False

True

10 / 10

Which of the below would best describe a dirty read?

a session being able to see uncommited data altered by another session

reading data direct from memory using pg_dirt

reading the data directly from file using a text editor such as vi or notepad

a session being able to see commited data altered by another session

Your score is

Created by

Paul Sammy

PostgreSQL 14 Internals Chapter 3

A quiz to test the knowledge of those reading and learning from Postgres 14 Internals book by Egor Rogov, covering topics in Chapter 3.

1 / 10

virtual IDs exist only in PGDATA/pg_vxid when not cached?

False

True

2 / 10

A page along with its tuples is read into the buffer cache with compression transformations to enhance cache efficiency?

True

False

3 / 10

Information about subtransactions is stored under?

PGDATA/pg_subtrans

PGDATA/pg_xid

PGDATA/pg_min

PGDATA/subtrans

4 / 10

at any one time Postgres can have several versions of a row?

True

False

5 / 10

The page header is located in the highest address?

True

False

6 / 10

When a row is created, its xmin value is set to the transaction ID of which command?

DELETE

CREATE

INSERT

COMMIT

7 / 10

What does an Item Pointer contain?

choose 3

tuple status

tuple offset from the start of the page

tuple length

tuple xid

8 / 10

Each page has a layer that usually consists of?

choose 2

free space

page header

undo segment

flashback block

9 / 10

Which function can we use to find the current transaction ID?

pg_current_id()

pg_current_xmin_id()

pg_current_commit_id()

pg_current_xact_id()

10 / 10

status of a subtransaction is written into CLOG?

True

False

Your score is

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