PostgreSQL Interview Questions and Answers
We are going to discuss the most interviewer asked PostgreSQL interview questions for the acknowledgment of future aspirants in this niche. PostgreSQL is one of the most advanced, object-relational database management systems and open-source developed by PostgreSQL Global Development Group at Berkeley Computer Science Department, University of California. With its strong hand on proven data integrity, reliability, architecture, extensibility, and excellent feature set, PostgreSQL has earned the prominence of being a superior and robust solution globally, thus highly increasing the employment base for this niche.
With the operation freedom of all major operating systems including UNIX, Windows, Linux, and Mac OS X; PostgreSQL supports images, text, video as well as sound, and includes programming interfaces for C, C++, Perl, Java, Tcl, Ruby, and Open Database Connectivity.
| Quick Questions about PostgreSQL | |
|---|---|
| What is the Latest Version of PostgreSQL? | 13.1 released on 12 November 2020 |
| When was PostgreSQL Initial released? | 8th July 1996 |
| What language does PostgreSQL use? | C Language |
| Who developed PostgreSQL? | Michael Stonebraker |
| What operating system use PostgreSQL? | Windows, Linux, macOS, OpenBSD |
Now, let’s discuss an advanced set of PostgreSQL interview questions further above for candidates searching for a near-future job change or going to start their career from the ground level.
Most Frequently Asked PostgreSQL Interview Questions
In PostgreSQL, there are 4 bytes of unique integers by default.
The PostgreSQL functions palloc and malloc are used for allocating memory.
plsqlODBC is the official PostgreSQL driver. Besides that, there are other third-party ODBC drivers such as Devart, which shall cost you some money.
The simplest way to check whether your server in PostgreSQL is running or not:
ps auxwww | grep postgres
In versions other than 8.3 you need to run this command
/Library/PostgreSQL/8.3/bin/postgres -D /Library/PostgreSQL/8.3/data
PgAdmin comes with built-in support to debug your Pl/PgSQL codes. However, in order to enable this, you need to compile and install a separate plug-in for PostgreSQL
Now, once you have set up a proper environment for debugging, go to edit /etc/postgresql/9.4/main/postgresql.conf and enable the debugger plugin.
Here are the steps to back up a single database in PostgreSQL. We shall be using the pg_dump tool as it dumps out the content of all the objects in the database to a single file.
Step 1: First of all, navigate to the PostgreSQL BIN folder:
C:\>cd C:\Program Files\PostgreSQL\9.2\bin
Step 2: Now, we shall execute the pg_dump program and use the following method to back up the examples database to the example.tar file to the c:\pgbackup\ folder.
pg_dump -U postgres -W -F t examples > c:\pgbackup\examples.tar
Step 3: Here is your backed up database
c:\pgbackup\dvdrental.tar
In PostgreSQL, the CTID field is one that exists in each and every PostgreSQL table, and it is unique for all records inside a table, which is used to denote the location of the tuples.
In PostgreSQL, a string constant is an arbitrary sequence of multiple characters that are bounded by single quotes (').
SELECT 'This' 'is' 'an' 'example'
Is equivalent to
SELECT 'This is an example'
Note that this is not the same as using double quotes (").
Benefits of PostgreSQL
- Enterprise-class functions and performance with an open-source database management system with unlimited development possibilities.
- Superior development possibility with diverse community purposed modules.
- Store Procedure functions can be used for a server environment.
- It offers diverse indexing techniques.
- Availability of full-text search
- Diverse extension functions and replications