feat: transactional CREATE/DROP

[usamoi]

No description provided.

[VoVAllen]

Can we add some tests for this?

[usamoi]

Can we add some tests for this?

I do not know how to test it.

[cutecutecat]

Can we add some tests for this?

I do not know how to test it.

Maybe we can start from what does this issue solved? Before and after?

[usamoi]

Can we add some tests for this?

I do not know how to test it.

Maybe we can start from what does this issue solved? Before and after?

The remote index created by CREATE will be removed if the transaction is aborted.

[cutecutecat]

In previous discussion, if a user enter ctrl+c before SQL CREATE INDEX returned. At backend, pgvecto.rs will generate a leaked index which is never used and unmaintained forever.

This PR would trigger a index cleaner every time user send ctrl+c.

To test it, we might need a python script to send abort and check whether the index file is cleared soon later, which could be done later.

[cutecutecat]

As flush caller is removed, do we still need IndexView.flush() and InstanceView.flush()?

[usamoi]

It's just moved to Commit.