Postgres and Open Source Experts

In PostgreSQL, the main difference between the BIGSERIAL, SMALLSERIAL, and SERIAL is the range of numbers they can hold/store.

Postgres allows us to add intervals to date time using the “+” and “-” operators. This post demonstrated various examples of adding intervals to DateTime values.

Use the INSERT query with comma-separated syntax to insert multiple rows into a Postgres table. To delete multiple rows, use the DELETE statement with IN clause.

In Postgres, creating a table that already exists will result in an error stating that the "relation already exists". To avoid such errors, the IF NOT EXISTS clause is used with the CREATE TABLE command.

This blog post explained date data types, functions, operators, formats, and intervals with the help of appropriate examples.

To check which PostgreSQL version is active on your system, users can run “psql –version” command from the command prompt, or the “SELECT VERSION()” command from SQL Shell.

To kill a process in Postgres, first, find the “pid” for all the processes, and then run the “pg_cancel_backend(pid)” and “pg_terminate_backend(pid)” commands.

PostgreSQL provides various sequence functions like SETVAL(), NEXTVAL(), CURRVAL(), and LASTVAL() to work with sequences efficiently.

To find the list of users, databases, schemas, or tables, the meta-commands like “\du”, “\l”, “\dn”, and “\dt” are used, respectively.

psql is a command-line interface used to perform various database tasks efficiently. For instance, using psql different commands can be executed to access, create, delete, or update a database, table, schema, etc.