Repository navigation
create_branch and create_tag replace an existing ref of the same name #4187
Description
Apache Iceberg version
0.12.0 (latest release)
Please describe the bug 🐞
Currently, create_branch and create_tag set the ref without checking whether it exists, so an existing branch is reset and loses its commits, and a tag moves. Java refuses an existing name with Ref dev already exists.
import tempfile
import pyarrow as pa
from pyiceberg.catalog.sql import SqlCatalog
cat = SqlCatalog("c", uri="sqlite:///:memory:", warehouse=f"file://{tempfile.mkdtemp()}")
cat.create_namespace("ns")
t = cat.create_table("ns.t", schema=pa.schema([("x", pa.int64())]))
t.append(pa.table({"x": [1]}))
s1 = t.current_snapshot().snapshot_id
t.manage_snapshots().create_branch(s1, "dev").create_tag(s1, "v1").commit()
t.append(pa.table({"x": [2]}), branch="dev")
t.append(pa.table({"x": [3]}))
t.manage_snapshots().create_branch(s1, "dev").commit()
print(t.scan().use_ref("dev").to_arrow()["x"].to_pylist())
# [1], should raise; the commit holding 2 is now on no ref
t.manage_snapshots().create_tag(t.current_snapshot().snapshot_id, "v1").commit()
print(sorted(t.scan().use_ref("v1").to_arrow()["x"].to_pylist()))
# [1, 3], should raise and leave v1 at [1]remove_branch and remove_tag check nothing either: remove_branch("main") is accepted and the table then reads as empty.
tested on pyiceberg 0.12.0 and main
Willingness to contribute
- I can contribute a fix for this bug independently
- I would be willing to contribute a fix for this bug with guidance from the Iceberg community
- I cannot contribute a fix for this bug at this time
Activity
tanmayrauth commentedon Oct 30, 2026
Can I work on this?