Support read inCommitTimestamp in Delta Lake history table

[chenjian2664]

Release notes

## Delta Lake
* Support read [in_commit_timestamp](https://github.com/delta-io/delta/blob/master/PROTOCOL.md#in-commit-timestamps) value in the `history` system table. ({issue}`25056`)

[ebyhr]

Could you add a test with a static resource? I guess the connector can't read such tables because inCommitTimestamps reader feature is unsupported.

[chenjian2664]

Just tested, Trino seems can read such table, for the reader seems no constraints?

[ebyhr]

You are right. It is writer only feature: https://github.com/delta-io/delta/blob/master/PROTOCOL.md#in-commit-timestamps

[chenjian2664]

@raunaqmorarka Would you like to have a look again?

[ebyhr]

Do we really fallback to "file modification timestamp"? Same for delta-lake.md.

[ebyhr]

I believe code readers can't understand why this logic returns OptionalLong.empty(). I would recommend supporting the field in this PR.

[chenjian2664]

Do you know to write the commitInfo in checkpoint file?
Current the whole method buildCommitInfoEntry is not covered by test or I am missing somewhere?
I see blow logic always is hit in the buildCommitInfoEntry in current tests.

        if (block.isNull(pagePosition)) {
            return null;
        }

[chenjian2664]

@ebyhr here shows the "fallback" to timestamp in first two versions

[ebyhr]

@chenjian2664 I'm not asking fallback to timestamp field. I'm asking if this PR fallback to "file modification timestamp" as you left a code comment. Does this assertion fail if we change file modification time of static resource? I believe the answer is no.

[chenjian2664]

oh, I think there is a gap about the "file modification timestamp", here what I refer "file modification timestamp" is -> timestamp field, while guess you are consider of the "creation/modification time of the metadata/log entry file"?
If so I would update the comment to "... read the timestamp", since it looks misleading

I use the "file modification timestamp" is refer from the https://github.com/delta-io/delta/blob/master/PROTOCOL.md#recommendations-for-readers-of-tables-with-in-commit-timestamps, which for readers it is said :

 readers can use the following rules:

1. For commits with version >= delta.inCommitTimestampEnablementVersion, readers should use the inCommitTimestamp field of the commitInfo action.
2. For commits with version < delta.inCommitTimestampEnablementVersion, readers should use the file modification timestamp.