Re: What's the best practice to compare the transaction with the checkpoint?

My question is that,  consider such a situation (in the order of time): 

1. toast create a file for a value V;

2. latest checkpoint;

3. use V (here the file is read);

4. delete the file when VACUUM deletes V;

5. crash, then when we recover from the latest checkpoint, the file will be accessed again but it has gone.

Is my understanding correct? Is this situation possible? Actually this question is my reason to think about the checkpointing things.

Best,

Jialun Zhang