Hi,

On 2/14/23 10:01 PM, houzj.f...@fujitsu.com wrote:

Here is the new version patch which addressed above comments.
I also fixed a bug for the deparsing of CREATE RULE that it didn't add
parentheses for rule action list.

I started testing this change set from this patch. I'm doing a mix of happy path, "making mistakes" path, and "real world" testing, and testing this both with unidirectional and "origin=none" replication.

I wanted to report an issue I came up with using one of my real world cases. I had previously built a demo scheduling app to demonstrate several features of PostgreSQL to help with various kinds of data synchronization[1]. The first example uses a series of functions and triggers[2] to keep a calendar table up-to-date.

I set up an experiment as such:

1. Create two different clusters. In each cluster, create a DB
2. On Cluster 1, run:

CREATE PUBLICATION ddl FOR ALL TABLES WITH (ddl='all');

3. On Cluster 2, run:

CREATE SUBSCRIPTION ddl CONNECTION '' PUBLICATION ddl;

4. On Cluster 1, run the commands in [2]. Note that I reproduced the error both by running the commands individually and as part of a single transaction.

5. The transactions (or single transaction) completes successfully on Cluster 1

5. Cluster 2 reports the following error:


2023-02-16 16:11:10.537 UTC [25207] LOG: logical replication apply worker for subscription "ddl" has started 2023-02-16 16:11:10.570 UTC [25207] ERROR: relation "availability" does not exist at character 279 2023-02-16 16:11:10.570 UTC [25207] CONTEXT: processing remote data for replication origin "pg_16733" during message type "DDL" in transaction 890, finished at 0/BF298CC0 2023-02-16 16:11:10.570 UTC [25207] STATEMENT: CREATE OR REPLACE FUNCTION public.availability_rule_bulk_insert ( IN availability_rule public.availability_rule, IN day_of_week pg_catalog.int4 ) RETURNS pg_catalog.void LANGUAGE sql VOLATILE PARALLEL UNSAFE CALLED ON NULL INPUT SECURITY INVOKER COST 100 AS $_$
            INSERT INTO availability (
                room_id,
                availability_rule_id,
                available_date,
                available_range
            )
            SELECT
                $1.room_id,
                $1.id,
                available_date::date + $2 - 1,
                tstzrange(
                    /** start of range */
                    (available_date::date + $2 - 1) + $1.start_time,
                    /** end of range */
/** check if there is a time wraparound, if so, increment by a day */
                    CASE $1.end_time <= $1.start_time
                        WHEN TRUE THEN (available_date::date + $2) + $1.end_time
                        ELSE (available_date::date + $2 - 1) + $1.end_time
                    END
                )
            FROM
                generate_series(
                    date_trunc('week', CURRENT_DATE),
date_trunc('week', CURRENT_DATE) + ($1.generate_weeks_into_future::text || ' weeks')::interval,
                    '1 week'::interval
                ) available_date;
        $_$
2023-02-16 16:11:10.573 UTC [15348] LOG: background worker "logical replication worker" (PID 25207) exited with exit code 1

I attempted this with both async and sync logical replication. In sync mode, the publisher hangs and is unable to accept any more writes.

When I went in and explicitly schema qualified the tables in the functions[3], the example executed successfully.

My high level guess without looking at the code is that the apply worker is not aware of the search_path to use when processing functions during creation. Provided that the publisher/subscriber environments are similar (if not identical), I would expect that if the function create succeeds on the publisher, it should also succeed on the subscriber.

Thanks,

Jonathan

[1] https://github.com/CrunchyData/postgres-realtime-demo
[2] https://github.com/CrunchyData/postgres-realtime-demo/blob/main/examples/demo/demo1.sql
[3] https://gist.github.com/jkatz/5655c10da1a4c8691094e951ea07b036

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