libc to libicu via pg_dump/pg_restore? - Mailing list pgsql-general

Hi,

I have a problem which I don't understand. I have and do:


instance a, libc based, PostgreSQL 15.10:

mydb=# \l mydb
                                                          List of databases
 Name |  Owner  | Encoding |   Collate   |    Ctype    | ICU Locale | Locale Provider | Access privileges
------+---------+----------+-------------+-------------+------------+-----------------+-------------------
 mydb | my_user | UTF8     | en_US.UTF-8 | en_US.UTF-8 |            | libc            |

$ pg_dump -Fc -Z1 -b mydb -f mydb.dump.gz
$ ls -l mydb.dump.gz
-rw------- 1 postgres postgres 14660308577 Feb  6 08:45 mydb.dump.gz


instance b, libicu based, PostgreSQL 17.2:
$ psql postgres

# create database mydb;
# \l mydb
                                                              List of databases
 Name |   Owner  | Encoding | Locale Provider |   Collate   |    Ctype    | Locale | ICU Rules | Access privileges
------+----------+----------+-----------------+-------------+-------------+--------+-----------+-------------------
 mydb | postgres | UTF8     | icu             | en_US.UTF-8 | en_US.UTF-8 | en-US  |           |

$ pg_restore -cC --if-exists --disable-triggers -d mydb mydb.dump.gz
pg_restore: error: could not execute query: ERROR:  cannot drop the currently open database
Command was: DROP DATABASE IF EXISTS mydb;
pg_restore: error: could not execute query: ERROR:  database "mydb" already exists
Command was: CREATE DATABASE mydb WITH TEMPLATE = template0 ENCODING = 'UTF8' LOCALE_PROVIDER = libc LOCALE =
'en_US.UTF-8';


pg_restore: error: could not execute query: ERROR:  insert or update on table "table_1" violates foreign key constraint
"..._fk"
DETAIL:  Key (dokument_id)=(1000033680) is not present in table "...".
Command was: ALTER TABLE ONLY myschema.table
   ADD CONSTRAINT table_fk FOREIGN KEY (dokument_id) REFERENCES myschema.dokument(id);


pg_restore: error: could not execute query: ERROR:  insert or update on table "table_2" violates foreign key constraint
"..._fk"
DETAIL:  Key (dokument_id)=(1000033740) is not present in table "dokument".
Command was: ALTER TABLE ONLY vostra2_str.nen_dokument
   ADD CONSTRAINT table_fk FOREIGN KEY (dokument_id) REFERENCES myschema.dokument(id);


I'm sorry, I sort of had to anonymize object names. But you should be able to get the gist of it. It's a dreaded
messagewhen importing. My goal is to export libc PostgreSQL 15 databases and import them into PostgreSQL 17 as libicu
baseddatabases to get away from glibc based sorting. I searched the net to find the "--disable-triggers" disable
triggerswhen running pg_restore but the errors still occur. 

What am I doing wrong or how can I better achieve that? Any help would be appreciated.

Thanks in advance.

Paul