[Feature Request] Support getting snapshot by timestamp

[vkorukanti]

Feature request

Which Delta project/connector is this regarding?

• Spark
• Standalone
• Flink
• Kernel
• Other (fill in here)

Overview

Currently, Kernel only supports reading the latest snapshot in a table (API here) This task is to add support for fetching a snapshot by timestamp.

interface Table
{
  /**
   * Get the latest snapshot that is create at given time or the first snapshot
   * committed after the given timestamp. Given timestamp in in seconds sinc
   * epoch in UTC timezone.
   */
  Snapshot getSnapshotAtOrAfterTimestamp(long secondsSinceEpochUTC)
}

Design Questions

• Should we even support the getSnapshotAtOrAfterTimestamp?
  • If yes, what should be the input timestamp? Timezone? seconds , micorseconds, milliseconds?
• How should the FileStatus returned by FileSystemClient.listFrom contain the modification time? Which timezone? Does the filesystem expose the mod time in UTC?

Willingness to contribute

The Delta Lake Community encourages new feature contributions. Would you or another member of your organization be willing to contribute an implementation of this feature?

• Yes. I can contribute this feature independently.
• Yes. I would be willing to contribute this feature with guidance from the Delta Lake community.
• No. I cannot contribute this feature at this time.