Experts in Postgres and Open Source Infrastructure

In Postgres, the TEXT data type accepts unlimited characters, while the behavior of the VARCHAR data type depends on its length parameter.

PostgreSQL provides several data types to work with the character/textual data, such as CHAR, TEXT, and VARCHAR. All these data types differ in length.

The TEXT data type is one of the character data types in PostgreSQL that is used to store an unlimited number of characters. It is used to create variable-length strings.

In PostgreSQL, the “||” operator and a built-in function named “CONCAT()” are used to concatenate multiple strings, characters, etc.

In Postgres, the “RETURNING” clause is used with the INSERT, DELETE or UPDATE queries to retrieve the newly inserted, deleted, or updated data.

In PostgreSQL, the “\l” statement and “pg_databases” catalog are used to show the list of databases. Use the “\l+” command to show databases with more details.

To create a primary key in Postgres, the user must specify the “PRIMARY KEY” keyword along with the name of the targeted column.

In PostgreSQL, the DISTINCT clause can be used with the COUNT() function to count only unique/distinct values of a table.

Foreign keys allows us to link the data of one table to others. The table referencing the foreign key is known as child table, while the table referenced by the foreign key is known as parent table.

In PostgreSQL, EXCEPT returns the rows that exist in the result set of the first SELECT query but not in the result set of the second SELECT query.