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

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

Choose 2 option

Postgres Server

Instance

Aurora

Quorum

2 / 20

Users should not modify the template0 database

False

True

3 / 20

What is the name of the mechanism used to store a row bigger than a page size?

BREAD

BAKE

TOAST

GROW

4 / 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

5 / 20

A schema can belong to more than one database?

True

False

6 / 20

Which fork keeps track of available space within pages?

vacuum space map

free space map

used space map

wal space map

7 / 20

Postgres uses a thread based process model?

False

True

8 / 20

What is the default standard size for a fork file?

5MB

1GB

1MB

5GB

9 / 20

Postgres by default has built in connection pooling abilities?

True

False

10 / 20

Postgres server spawns a new backend session for each connection?

True

False

11 / 20

What 3 files/forks as a minimum make up a table on disk?

visiblilty map

Main fork

free space map

table map

12 / 20

Which of below are predefined schemas?

choose 3

pg_temp

pg_toast

information_schema

pg_schema

13 / 20

To be able to restore data consistency, Postgres maintains

undo segments (UNDO)

online redo logs (ORL)

write-ahead log (WAL)

rollback segments (RBS)

14 / 20

System Catalog tables begin with which prefix?

pg_

dba_

cat_

sys_

15 / 20

What is the purpose of autovacuum?

Removes stale data from tables and indexes

Rebuilds indexes with b level greater than 2

Performs a backup of WAL logs

Deletes old logs and traces on disk

16 / 20

What is a schema?

A memory area used to cache data from LRU chains

The name used to refer to a super user account

This is the same as a user in Postgres

Namespace that store all objects of a database

17 / 20

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

System Catalog

Sys Catalog

Sysaux Catalog

Sysasm Catalog

18 / 20

What is the purpose of the template0 database?

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

Useful for creating development schemas

No such database

Useful for Postgres support Services to debug issues

19 / 20

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

pg_symlinks

pg_tablespace

pg_tabspace

pg_tblspc

20 / 20

How many files or forks on disk will a 10Mb table with no index have?

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

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

False

True

2 / 10

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

True

False

3 / 10

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

Read Committed

Repeatable Read

Read Uncommitted

Serializable

4 / 10

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

False

True

5 / 10

What is the default Isolation Level?

Repeatable Read

Read Committed

Read Uncommitted

Serializable

6 / 10

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

BEGIN ISOLATION LEVEL REPEATABLE READ;

SET ISO=REPEATABLE_READ;

CREATE EXTENSTION REPEATABLE_READ;

ALTER SYSTEM SET ISO=REPEATABLE_READ;

7 / 10

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

True

False

8 / 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 once, 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.

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

9 / 10

The SQL standard specifies three isolation levels?

True

False

10 / 10

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

False

True

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

Postgres table physical data files are always cross compatible across platforms?

False

True

2 / 10

Tuples can also be referred to as columns?

True

False

3 / 10

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

pg_current_commit_id()

pg_current_xmin_id()

pg_current_id()

pg_current_xact_id()

4 / 10

The page header stores checksum and the sizes of the other parts of the page?

True

False

5 / 10

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

False

True

6 / 10

indexes do not use row versioning?

True

False

7 / 10

Page free space can often become fragmented?

True

False

8 / 10

CLOG files are stored in which directory?

PGDATA/pg_commit

PGDATA/pg_xact

PGDATA/clog

PGDATA/pg_clog

9 / 10

Which 2 items does a Virtual XID consist of?

checksum

sequential number

xmin

backend process ID

10 / 10

If a transaction aborts, all page changes are reverted(rolled back) in place?

True

False

Your score is

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