This PR was merged into the 5.2 branch.
Discussion
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[Messenger] Don't lock tables or start transactions
| Q | A
| ------------- | ---
| Branch? | 5.2
| Bug fix? | yes
| New feature? | no
| Deprecations? | no
| Tickets |
| License | MIT
| Doc PR |
I was so sure my PR #40336 fixed the doctrine-messenger issue once and for all. But it had a very silent bug..
This has been tricky to debug and find because the `PDO` behaves differently in PHP 7.4 compared to PHP 8.
| Scenario | Command | Is executed in transaction | Method that calls `PostgreSqlConnection::getTriggerSql()` |
| --| -- | -- | -- |
| A | `messenger:setup-transports` | No | `setup()`
| B| `doctrine:schema:create` | No | `getExtraSetupSqlForTable()`
| C | `doctrine:migration:diff` | Yes by default, but it can be configured | `getExtraSetupSqlForTable()`
PR #40055 fixed scenario C on PHP 8, but that also broke scenario B on PHP 7.4 and PHP 8.
In PR #40336 I was wrong claiming:
> We don't need COMMIT because the transaction will commit itself when we close the connection.
The result was the we removed all the errors messages from the 3 scenarios. But scenario B will produce some SQL that is actually never committed. IE it will silently fail.
I've been trying to figure out a good solution to how or when to start a transaction. I tried out @fbourigault [suggestion](https://github.com/symfony/symfony/pull/40336#issuecomment-790622951) but that would be the same fix as #40055.
---------------
We need a transaction because the SQL includes a `LOCK TABLE`, however, I cannot see a strict need for it. This PR removes `LOCK TABLE` and all transaction juggling. It all seams to work.
I would be happy to get thorough feedback on this PR so we can end the chapter of constantly adding bugs to this part of the component.
@dunglas, you added `LOCK TABLE` in your initial version of this class in https://github.com/symfony/symfony/pull/35485, could you share some knowledge if this is a good or bad idea?
Commits
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26061a131d Dont lock tables or start transactions
9978ba805f