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This is the Education section of the Command Prompt Website. Here you will find blogs specifically about how to use Postgres and related technologies.

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How to Query Arrays in PostgreSQL

To query the ARRAY data in Postgres, the SELECT statement is used. Postgres allows us to query the data of an entire array or a specific array index.

How to Query Date and Time in PostgreSQL

In PostgreSQL, different built-in functions are used along with the SELECT statement to query date and time. This blog post explained how to query date and time in Postgres using suitable examples.

PostgreSQL DELETE USING Statement - Drop Duplicate Rows

In Postgres, the COUNT() function finds duplicate records. While the “DELETE USING” statement drops the duplicates.

Configuring Binary Replication with pgBackRest

PostgreSQL has two forms of native replication: logical replication and binary replication. Logical replication offers tuple-by-tuple changes streamed from a primary server to a secondary server. Binary replication, also known as physical replication, sends changes at a disk block level.

Binary replication allows for backing up an entire database and recovering it to a specific point in time, called point-in-time-recovery (PITR). PostgreSQL accomplishes this by using a write-ahead log (WAL), which details the transactions that occur. This tutorial provides a guide for implementing binary replication between a primary and secondary server.

Executing Citus Across Nodes

Welcome back to our Citus blog series! So far in this series, we have installed and configured the Citus extension for PostgreSQL. Now that we are up and running, it is time to distribute some data.

Let’s begin by inserting some sample data for demonstration purposes. First, we need a table in which to put the data.

How to Use REPEAT() Function in PostgreSQL

The REPEAT() function in Postgres is a string function that retrieves a string consisting of the given string repeated an ‘n’ number of times.

How to Get a Day From a Date in PostgreSQL

To get a day from a date, specify the “Day” as the first argument and a specific date, timestamp, or interval as the second argument to the EXTRACT().

Postgres SQRT() Function With Practical Examples

In PostgreSQL, the SQRT() is a built-in mathematical function that accepts a positive numeric value and retrieves its square root.

Postgres Modulo Function With Examples

PostgreSQL provides a built-in math function named MOD() that accepts numeric values as arguments, performs division, and retrieves the remainder after division.

Difference Between DIV() and MOD() Function in PostgreSQL

The DIV() and MOD() functions in Postgres perform the division on numeric values. However, the DIV() function retrieves a quotient while the MOD() function retrieves the remainder.