Postgres and Open Source Experts

Postgres supports a couple of native JSON operators to query the data from a JSON column. These operators include a short arrow “->” and a long arrow “->>”.

In PostgreSQL, the TO_TIMESTAMP() function is used to convert a Unix or Posix Timestamp to a date or time value.

The CASE statement is one of the conditional expressions that is used to create conditional queries. Postgres supports two forms of the CASE statement: A Searched CASE and a simple CASE.

The NOT EQUAL operator is one of the comparison operators that check if the input values are equal or not. It is symbolized as “!=” or “<>”.

Postgres offers various ways to convert a TIMESTAMP to a DATE, such as TO_CHAR() function, CAST operator, EXTRACT function, etc.

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.