Postgres and Open Source Experts

PostgreSQL allows us to import CSV files to Postgres tables or export Postgres tables to CSV files using SQL Shell (psql). To do that, the “\COPY” command is used.

PostgreSQL is a powerful object-relational database management system that offers a growing range of extensions to provide features and functionality unmatched by others. One such extension that has recently become fully open-source is Citus. Citus Data originated in 2011, was open sourced as an extension to PostgreSQL in 2016, and was acquired by Microsoft in 2019. As of June 2022, all Enterprise features have been made available for free, and Citus is now 100% open source!

Postgres provides an INNER JOIN clause to combine the records of multiple tables based on a specific condition/criteria.

Postgres provides a couple of ways to drop all the tables of a Postgres database, such as dropping the complete schema or removing the schema’s tables individually.

In PostgreSQL, the COALESCE() function and the IS NULL operator are used to find and replace the null values with some default values.

The INTERVAL keyword is used to define an interval in Postgres. This blog explained the usage of the INTERVAL data type in Postgres via suitable examples.

The ALTER TABLE command in PostgreSQL is used to alter the tables' structure, such as adding columns, renaming columns/tables, dropping columns, modifying constraints, etc.

In Postgres, the standard “information_schema”, a system catalog table named “pg_namespace”, and the “\dn” command is used to get the list of available schemas.

PostgreSQL provides different built-in commands and queries to get the list of all the tables, such as the “\dt” command, “pg_tables”, “information_schema”, etc.

In Postgres, the IS NULL operator tests whether an expression/column contains a null value. It can be used with different statements, such as SELECT, UPDATE, etc.