Postgres and Open Source Experts

To get the Unix Timestamp in PostgreSQL, the EXTRACT() and DATE_PART() functions are used with the EPOCH argument.

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.

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.

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

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.

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

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().

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

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

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.