Re: BUG #17434: CREATE/DROP DATABASE can be executed in the same transaction with other commands

On 08.08.22 17:21, Yugo NAGATA wrote:
>>> In fact, the result of IsInTransactionBlock does not make senses at
>>> all in pipe-line mode regardless to the fix. ANALYZE could commit all
>>> previous commands in pipelining, and this may not be user expected
>>> behaviour.
>> This seems pretty much isomorphic to the fact that CREATE DATABASE
>> will commit preceding steps in the pipeline.
> I am not sure if we can think CREATE DATABASE case and ANLALYZE case
> similarly. First, CREATE DATABASE is one of the commands that cannot be
> executed inside a transaction block, but ANALYZE can be. So, users would
> not be able to know ANALYZE in a pipeline causes a commit from the
> documentation. Second, ANALYZE issues a commit internally in an early
> stage not only after it finished successfully. For example, even if
> ANALYZE is failing because a not-existing column name is specified, it
> issues a commit before checking the column name. This makes more hard
> to know which statements will be committed and which statements not
> committed in a pipeline. Also, as you know, there are other commands
> that issue internal commits.

This has broken the following use:

parse: create temporary table t1 (a int) on commit drop
bind
execute
parse: analyze t1
bind
execute
parse: select * from t1
bind
execute
sync

I think the behavior of IsInTransactionBlock() needs to be further
refined to support this. If we are worried about external callers,
maybe we need to provide a separate version. AFAICT, all the callers of
IsInTransactionBlock() over time have been in vacuum/analyze-related
code, so perhaps in master we should just move it there.