Experts in Postgres and Open Source Infrastructure

The Postgres LENGTH() function accepts a string as an argument and calculates the total number of characters in that particular string.

PostgreSQL provides a pg_relation_size() function to get the size of a particular table. The “pg_size_pretty()” function is used to get the table’s size in a human-readable format like KBs, MBs.

To rename a database in Postgres, specify an ALTER DATABASE command, followed by the database’s old name, and after that, specify the RENAME TO clause followed by the database’s new/modified name.

CURRENT_DATE is one of the Postgres built-in date functions that retrieve the current/today’s date. It doesn’t take any argument.

PostgreSQL offers a GRANT statement that is used to assign privileges to the database objects. In Postgres, you can grant all privileges to a user via the "GRANT ALL" statement.

UNIQUE constraints can be dropped by running the ALTER TABLE command with the "DROP CONSTRAINT" clause followed by the constraint’s name.

PostgreSQL provides a built-in DIV() function that takes two numeric values as arguments, performs division on them, and retrieves the resultant integer.

Postgres doesn’t support the “IF NOT EXISTS” option for the CREATE DATABASE command. To achieve the functionality of the “IF NOT EXISTS” option, a subquery can be used in Postgres.

In Postgres, double hyphen “--” sign is used for single-line comments, while to use multi-line comments, you need to enclose the comments within “/*” and “*/”.

To create an array in Postgres, users must specify the column name, then the data type, followed by the square brackets “[]”.