[feature request] Delta table API method to rollback/revert latest committed changes

[dattawalake]

Thank you for great work !

I would like to have a api method ,to rollback /revert latest changes simply like DeltaTable.rolleback(), currently I am handling this scenario just removing latest version of log file and checkpoint file if any with same latest version . just to avoid rewriting/remove data files, vacuum will take care .

In my scenario , ETL pipeline has some steps after delta table merge, if any failure after this step, I need to revert the changes from delta table .

I am using below code snippet -

val deltaTable = DeltaTable.forPath(spark, path)

  val lastOperationDF = deltaTable.history(1)
  var currentVersion:Long=0
  var readVersion:Long=0
  lastOperationDF.select("version", "readVersion")
    .collect()
    .foreach( r => {
      currentVersion = r.getLong(0)
      readVersion = r.getLong(1)
    })

  val revertVersionFileName = appContext.deltaLogFileNameFormat.get.format(currentVersion).concat(".json")
  val readVersionFileName = appContext.deltaLogFileNameFormat.get.format(readVersion).concat(".json")
  revertPath = newPath.stripSuffix("/").concat("/_delta_log/").concat(revertVersionFileName)
  currentPath = newPath.stripSuffix("/").concat("/_delta_log/").concat(readVersionFileName)

//Delete code to delete latest version log file and and corresponding checkpoint file if any exist for same version.

In my case as of now I am having this case with non partitioned tables so not sure how to handle checkpoint files with partitioned tables.

Thanks

[MrPowers]

Delta Lake rollback command now exists: https://delta.io/blog/2022-10-03-rollback-delta-lake-restore/

Hope you find the command useful!