In PostgreSQL, the dollar-quoted string constants ($$) is used in user-defined functions and stored procedures. In PostgreSQL, you use single quotes for a string constant like this: select ‘String constant’; When a string constant contains a single quote (‘), you need to escape it by doubling up the single quote.

What is $$ language Plpgsql?

PL/pgSQL (Procedural Language/PostgreSQL) is a loadable procedural programming language supported by the PostgreSQL. PL/pgSQL, as a fully featured programming language, allows much more procedural control than SQL, including the ability to use loops and other control structures.

What is delimiter in PostgreSQL?

DELIMITER. Specifies the character that separates columns within each row (line) of the file. The default is a tab character in text format, a comma in CSV format. This must be a single one-byte character.