Re: BUG #18118: bug report for COMMIT AND CHAIN feature

On Wed, 2023-09-20 at 09:31 +0000, PG Bug reporting form wrote:
> PostgreSQL version: 14.9
> Operating system:   centos7
> Description:       
>
> COMMIT(280a408b48d5ee42969f981bceb9e9426c3a344c) provides a way to support
> chained commits. During recent development, I found that it left a flaw.
>
> The defect can be reproduced as follows:
>
> START TRANSACTION ISOLATION LEVEL SERIALIZABLE; COMMIT;
> START TRANSACTION ISOLATION LEVEL REPEATABLE READ\; savepoint s\; COMMIT AND
> CHAIN;
> SHOW transaction_isolation; -- transaction is active at this point
> COMMIT;
>
> will get:
> postgres=*# SHOW transaction_isolation; -- transaction is active at this
> point
>   transaction_isolation
> -----------------------
>   serializable
> (1 row)

I tried to reproduce that and failed, both with v14 and v16.

For me, "transaction_isolation" is "repeatable read".

Yours,
Laurenz Albe