How to create a temporary function in PostgreSQL?

The path to temporary functions

Opt for pg_temp schema

Use the pg_temp schema, a unique temporary schema created per session, to seamlessly craft your temporary function:

-- Function creation in the elusive pg_temp schema
CREATE FUNCTION pg_temp.my_temp_function() RETURNS text AS $$
BEGIN
    RETURN 'Temporary content';
END;
$$ LANGUAGE plpgsql;

-- The spotlight moment, function execution
SELECT pg_temp.my_temp_function();


Using pg_temp harnesses PostgreSQL's inbuilt cleanup mechanism which self-destructs the pg_temp schema when the session ends. This alleviates the chore of manual cleanup.

Reach for DO blocks

When your operations are a one-hit wonder, an anonymous DO block can execute procedural code without the hitches of defining a function:

DO $$
BEGIN 
    -- Your time to shine is here
END $$;


While on the surface DO blocks may not bear the label of functions, they can fill those shoes for short-lived tasks.

Evaluate efficiency in production

Temporary solutions might seem like the knight in shining armor for development or testing environments but tread with caution in production. Efficient application of functional indexes or cursors requires proper understanding of their performance implications.

Consider prepared statements

When your SQL execution seems like a broken record with variable parameters, prepared statements might just be the solution you need:

-- No room for procrastination, preparing the statement
PREPARE temp_statement (int, int) AS
    SELECT $1 + $2;

-- All eyes on me, executing the prepared statement
EXECUTE temp_statement(5, 10);

-- Finally, a break from repetitive chores
DEALLOCATE temp_statement;


Reinvent temporary structures

The need for a temporary function often hints at a bunny hole worth exploring. Have you considered stored procedures or user-defined functions as a permanent fix for recurring operations?