Postgres and Open Source Experts

In PostgreSQL, the JSON_AGG() function is used to combine multiple values into a single JSON array. The return type of the JSON_AGG() function is JSON.

Postgres’ ALTER DATABASE command modifies the already existing databases, such as renaming a database, modifying the database attributes, changing the database ownership, etc.

To set Windows PATH for Postgres tools, open System Properties > “Environment Variable” > “Path” variable > “Edit..” button > “NEW” button > specify Postgres bin directory’s path > hit the “OK” button.

In Postgres, different commands, such as CREATE TABLE AS SELECT, CREATE TABLE AS TABLE, etc. are used to duplicate a table with or without data.

There are various ways to start, stop, or restart the Postgres server on Windows, such as using the “net start” command, “pg_ctl” utility, or “services” manager.

A schema in database management systems represents a set of rules that regulate/handle a database. It is a logical structure that holds various database objects like views, tables, indexes, sequences, etc. In Postgres, “public” is a Default schema. So, by default, Postgres users can access the "public" schema and create objects in it, such as views, tables, etc.

The SET SEARCH_PATH command, however, allows a user to set any other …

In PostgreSQL, use the CREATE DATABASE command along with the “WITH TEMPLATE” parameter to copy or clone a database.

In PostgreSQL, conditional expressions are used to select one of the multiple values based on the Boolean condition.

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 “->>”.

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.