Re: DB migration : Sybase to Postgres

Em qui., 25 de mai. de 2023 às 08:30, Sengottaiyan T <techsenko(at)gmail(dot)com>
escreveu:

> Is there an option to set novalidate constraints in postgres? In my source
> Sybase DB, table structures are not defined properly (only primary keys
> exist and no foreign key) - I'm making necessary changes on target Postgres
> DB (created tables, identifying relationship between table columns with
> respective team). After creating proper structure on target, the next step
> is to load data - I'm sure there will be a lot of errors during initial
> data load (no parent record found). How to handle it?
>
>>
>> Other options:

create all foreign keys before importing your data and do ...

This way table triggers are disabled for all users;
ALTER TABLE T1 DISABLE TRIGGER ALL; ALTER TABLE T2 DISABLE TRIGGER ALL; ALTER
TABLE T3 DISABLE TRIGGER ALL;
--Import all your data
ALTER TABLE T1 ENABLE TRIGGER ALL; ALTER TABLE T2 ENABLE TRIGGER ALL; ALTER
TABLE T3 ENABLE TRIGGER ALL;

or

This way table triggers are disabled for this session only;
SET SESSION_REPLICATION_ROLE = REPLICA;
--Import all your data
SET SESSION_REPLICATION_ROLE = ORIGIN;

Obviously if your data doesn't have correct foreign keys matching to their
parent you'll never be able to do a dump/restore properly.

Marcos