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

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

Search Path

Directory Path

Access Path

Schema Path

2 / 20

What is the point of the pg_global tablespace?

stores temporary tables that are common to the whole cluster

stores user tables that are common to the whole cluster

stores system catalog objects that are common to the whole cluster

stores WAL logs used for global replication

3 / 20

What is the name of the catalog that stores metadata for all cluster objects?

System Catalog

Sys Catalog

Sysasm Catalog

Sysaux Catalog

4 / 20

A single Postgres Instance can server only one database?

False

True

5 / 20

How many rows in a page does Postgres aim to have before considering TOAST?

6 / 20

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

True

False

7 / 20

Users should not modify the template0 database

True

False

8 / 20

The information_schema schema provides information on Postgres release notes?

True

False

9 / 20

What is the purpose of the postgres database?

a template for all the other database

regular database that you can use at your discretion

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

No such database

10 / 20

If we create a new tablespace which directory will symbolic links be created from?

pg_symlinks

pg_tablespace

pg_tblspc

pg_tabspace

11 / 20

Who is the Author of the Postgres 14 Internals book?

Paul Sammy

Sam Altman

Egor Rogov

Dan Brown

12 / 20

Files are logically split into pages?

True

False

13 / 20

Postgres by default has built in connection pooling abilities?

False

True

14 / 20

Which of below are predefined schemas?

choose 3

pg_schema

information_schema

pg_temp

pg_toast

15 / 20

What is the default standard size for a fork file?

1MB

5MB

5GB

1GB

16 / 20

What command is used to create the Postgres cluster?

Initialize

StartNewPG

CreateCluster

CreatePGC

17 / 20

Some System Catalog tables are common to all databases in the cluster?

True

False

18 / 20

What is the purpose of wal writer?

writes WAL entries to disk

collects usage statistics for the instance.

flushes dirty pages to disk.

executes checkpoints

19 / 20

What is the process first launched at server start?

pginit

init

postgres

postman

20 / 20

What is the name of the directory that contains the files related to the Postgres cluster?

PGDATA

PGCORE

PGBASE

PGTIPS

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

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

True

False

2 / 10

Lost updates are forbidden by the standard at all isolation levels?

False

True

3 / 10

Which of the below are valid Isolations Levels?

choose 2

Random Scatter

Rollback Read

Read Committed

Serializable

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 issue a rollback.

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

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

5 / 10

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

Read Uncommitted

Serializable

Read Committed

Repeatable Read

6 / 10

What is the default Isolation Level?

Serializable

Read Committed

Repeatable Read

Read Uncommitted

7 / 10

Based on Snapshot Isolation use of MVCC which of the below are permitted?

choose 3

Repeatable Read

Read Uncommitted

Serializable

Read Committed

8 / 10

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

CREATE EXTENSTION REPEATABLE_READ;

SET ISO=REPEATABLE_READ;

BEGIN ISOLATION LEVEL REPEATABLE READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

9 / 10

The SQL standard specifies three isolation levels?

False

True

10 / 10

A phantom read anomaly occurs when?

The same transactions issues a commit, then a rollback to restore data to its original value

The same transaction executes two identical queries returning a set of rows that satisfy a particular condition, while another transaction also queries this same data.

A transactions inserts a null value into a not null columns and commits

The same transaction executes two identical queries returning a set of rows that satisfy a particular condition, while another transaction adds some other rows satisfying this condition and commits.

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

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

pg_current_id()

pg_current_xact_id()

pg_current_xmin_id()

pg_current_commit_id()

2 / 10

Rows of TOAST tables are handled in such a way that they are never update?

True

False

3 / 10

Indexes values also support multi versioning with several versions of an index value existing at any point in time?

False

True

4 / 10

The page header is located in the highest address?

False

True

5 / 10

a transaction containing a savepoint is will still be considered as only a single transaction?

True

False

6 / 10

Which 2 items does a Virtual XID consist of?

checksum

backend process ID

sequential number

xmin

7 / 10

Information about subtransactions is stored under?

PGDATA/subtrans

PGDATA/pg_min

PGDATA/pg_subtrans

PGDATA/pg_xid

8 / 10

Tuples can also be referred to as columns?

True

False

9 / 10

To identify different versions of one and the same row, PostgreSQL marks each of them with which two value?

xmas

xid

xmin

xmax

10 / 10

CLOG Pages are never cached in memory?

True

False

Your score is

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