Re: Patch: Add parse_type Function

[Erik Wienhold]

On 2024-02-18 20:00 +0100, Pavel Stehule wrote:
> The overhead of parse_type_and_format can be related to higher planning
> time. PL/pgSQL can assign composite without usage FROM clause.

Thanks, didn't know that this makes a difference.  In that case both
variants are on par.

        BEGIN;
        
        CREATE FUNCTION format_with_parse_type(text)
        RETURNS text
        LANGUAGE plpgsql
        STABLE STRICT
        AS $$
        DECLARE
            p record := parse_type($1);
        BEGIN
            RETURN format_type(p.typid, p.typmod);
        END
        $$;
        
        CREATE FUNCTION format_with_to_regtypmod(text)
        RETURNS text
        LANGUAGE plpgsql
        STABLE STRICT
        AS $$
        BEGIN
            RETURN format_type(to_regtype($1), to_regtypmod($1));
        END
        $$;
        
        COMMIT;

Results:

        SELECT format_with_parse_type('interval second(0)');

        pgbench (17devel)
        transaction type: format_with_parse_type.sql
        scaling factor: 1
        query mode: simple
        number of clients: 1
        number of threads: 1
        maximum number of tries: 1
        duration: 10 s
        number of transactions actually processed: 253530
        number of failed transactions: 0 (0.000%)
        latency average = 0.039 ms
        initial connection time = 1.846 ms
        tps = 25357.551681 (without initial connection time)

        SELECT format_with_to_regtypmod('interval second(0)');

        pgbench (17devel)
        transaction type: format_with_to_regtypmod.sql
        scaling factor: 1
        query mode: simple
        number of clients: 1
        number of threads: 1
        maximum number of tries: 1
        duration: 10 s
        number of transactions actually processed: 257942
        number of failed transactions: 0 (0.000%)
        latency average = 0.039 ms
        initial connection time = 1.544 ms
        tps = 25798.015526 (without initial connection time)

-- 
Erik