RyanLin5967 opened a new issue, #10886:
URL: https://github.com/apache/paimon/issues/10886

   ### Search before asking
   
   - [x] I searched in the [issues](https://github.com/apache/paimon/issues) 
and found nothing similar.
   
   
   ### Paimon version
   
   pypaimon 2.1.0. `rollback_helper.py` is unchanged on master.
   
   ### Compute Engine
   
   Python API (pypaimon 2.1.0, Python 3.12.16, pyarrow 19.0.1) on a local 
filesystem catalog. Spark 3.5.6 with paimon-spark-3.5_2.12 2.1.0 on Java 17 
expires the snapshots, since pypaimon has no snapshot expiration.
   
   ### Minimal reproduce step
   
   Currently, when the tag's snapshot has expired, pypaimon's `rollback_to` 
writes that snapshot file back but leaves the EARLIEST hint on the old earliest 
id, so once new commits reach that id, reads take it as the earliest snapshot 
and skip the commits before it. Spark's `rollback` procedure in its place sets 
EARLIEST to 2, and every read is right.
   
   ```python
   import os
   import pyarrow as pa
   from pyspark.sql import SparkSession
   from pypaimon import CatalogFactory, Schema
   
   spark = (SparkSession.builder
            .config("spark.jars", "paimon-spark-3.5_2.12-2.1.0.jar")
            .config("spark.sql.extensions", 
"org.apache.paimon.spark.extensions.PaimonSparkSessionExtensions")
            .config("spark.sql.catalog.paimon", 
"org.apache.paimon.spark.SparkCatalog")
            .config("spark.sql.catalog.paimon.warehouse", "file://" + 
os.path.abspath("wh"))
            .getOrCreate())
   cat = CatalogFactory.create({"warehouse": "wh"})
   cat.create_database("db", True)
   sch = pa.schema([("k", pa.int64())])
   cat.create_table("db.t", Schema.from_pyarrow_schema(sch), False)
   
   
   def write(k):
       wb = cat.get_table("db.t").new_batch_write_builder()
       w, c = wb.new_write(), wb.new_commit()
       w.write_arrow(pa.table({"k": [k]}, schema=sch))
       c.commit(w.prepare_commit())
   
   
   def read(opts):
       rb = cat.get_table("db.t").copy(opts).new_read_builder()
       return 
sorted(rb.new_read().to_arrow(rb.new_scan().plan().splits())["k"].to_pylist())
   
   
   for k in (1, 2, 3, 4, 5):
       write(k)
   cat.get_table("db.t").create_tag("v2", 2)
   spark.sql("CALL paimon.sys.expire_snapshots(table => 'db.t', retain_max => 
1, retain_min => 1)").collect()
   cat.get_table("db.t").rollback_to("v2")
   for k in (6, 7, 8):
       write(k)
   
   print(open("wh/db.db/t/snapshot/EARLIEST").read())
   # 5, should be 2
   sm = cat.get_table("db.t").snapshot_manager()
   s2, s3, s5 = (sm.get_snapshot_by_id(i).time_millis for i in (2, 3, 5))
   print(read({"incremental-between-timestamp": f"{s2},{s5}"}))
   # [8], should be [6, 7, 8]
   print(read({"scan.timestamp-millis": str(s3)}))
   # ValueError: No snapshot found with timestamp earlier than or equal to 
1793326991626ms., should be [1, 2, 6]
   ```
   
   ### What doesn't meet your expectations?
   
   After `rollback_to("v2")` the EARLIEST hint is 2 and the reads return `[6, 
7, 8]` and `[1, 2, 6]`.
   
   ### Anything else?
   
   A new Spark session reads the same window as `[8]` too.
   
   ### Are you willing to submit a PR?
   
   - [ ] I'm willing to submit a PR!


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