function ulid_create(timestamp with time zone) does not exist

[basaran]

Hello,

Following the readme, execution of ulid_create with a timestamp returns the following error:

SELECT ulid_create(now() - '37 days'::interval);

ERROR:  function ulid_create(timestamp with time zone) does not exist
LINE 1: SELECT ulid_create(now() - '37 days'::interval);
               ^
HINT:  No function matches the given name and argument types. You might need to add explicit type casts.
SQL state: 42883
Character: 8

[MartinRamm]

It took me quite a while to figure it out, but the problem seems to be incomplete installation instructions in the readme of this repository. I got the following code to work using docker, you should be able to adapt it to your system:

FROM postgres:13.1

RUN apt-get update &&                                    \
# Install ulid extension
    apt install -y build-essential                       \
        git                                              \
        postgresql-server-dev-13 &&                      \
    cd "$HOME" &&                                        \
    git clone https://github.com/edoceo/pg-ulid.git &&   \
    cd pg-ulid &&                                        \
    git clone https://github.com/skeeto/ulid-c.git &&    \
    cd ulid-c &&                                         \
    make &&                                              \
    cd .. &&                                             \
    make &&                                              \
    make install-strip &&                                \
#register ulid extension with postgres (this code is run right after postgres starts initially)
    echo "CREATE EXTENSION pg_ulid;"                     \
        > /docker-entrypoint-initdb.d/ulid.sql &&        \
# cleanup
    rm -rf /tmp/* /var/tmp/* /var/lib/apt/lists/*

[basaran]

I had followed the same steps, it's only the SELECT ulid_create(now() - '37 days'::interval); throwing the error, select ulid_create() is returning the ulid without any issues.

What's more puzzling are the ulid type creation scripts are commented out, perhaps it's a personal to do for the author. I'm referring to the sql script inside the built folder:

-- CREATE FUNCTION ulid_create;
-- CREATE TYPE ulid AS {
--      a int8,
--      b int8,
-- }

-- CREATE FUNCTION base36_filter(cstring)
-- RETURNS base36
-- AS '$libdir/base36'
-- LANGUAGE C IMMUTABLE STRICT;
--
-- CREATE FUNCTION base36_out(base36)
-- RETURNS cstring
-- AS '$libdir/base36'
-- LANGUAGE C IMMUTABLE STRICT;
--
-- CREATE TYPE base36 (
--   INPUT          = base36_in,
--   OUTPUT         = base36_out,
--   LIKE           = integer
-- );

anyhow, this seems to be the fastest generator at this time. I posted benchmarks in #3

https://github.com/schinckel/ulid-postgres/blob/master/ulid.sql

This library has some sql based functions to extract the timestamp information, so I think for the moment I will use them.

Have you been able to get the SELECT ulid_create(now() - '37 days'::interval); working with your docker image?