Folks, question about StarRocks 4.1.1 - how do I get AUTO refresh mode on for iceberg-driven materialized views? There seems to be support in the code for AUTO mode, and I see the article on medium mentioning refresh_mode="auto" (even @Rocky gives a similar output), yet, when I try to enable it, I am getting an error that only INCREMENTAL or PCT is supported - no AUTO.

In StarRocks 4.1.1, the

refresh_mode

property was indeed introduced to support more flexible refresh strategies for materialized views (MVs), particularly those driven by Iceberg and Paimon append-only tables. However, you are likely encountering one of the following restrictions or behavior changes introduced in this version: 1. You cannot

ALTER

a legacy MV to

AUTO

According to the documentation for StarRocks 4.1, you cannot change an existing "legacy" materialized view (one created without

refresh_mode

or using the default

PCT

mode) to

AUTO

or

INCREMENTAL

using an

ALTER

statement. * The Fix: You must drop and recreate the materialized view from scratch with the property defined in the

PROPERTIES

block. 2. Validation Constraints in v4.1.1 The error message

only INCREMENTAL or PCT is supported - no AUTO

suggests a validation check. While

AUTO

is supported in the broader v4.1 release, StarRocks 4.1.1 specifically introduced several "hardening" changes for these new modes: * Query Rewrite: Automatic query rewrite is currently disabled for MVs with

refresh_mode

set to

INCREMENTAL

or

AUTO

(Issue #74512). This was done to ensure correctness while the Incremental MV (IMV) engine matures. * Command Rejection: In 4.1.1, both

FORCE

refresh and partition-specific refreshes are explicitly rejected for

AUTO

or

INCREMENTAL

MVs. If you are trying to trigger a refresh with these flags while setting the mode, it may fail. 3. Syntax and Requirements Ensure your creation syntax looks like this (noting that

refresh_mode

is a property):

sql
CREATE MATERIALIZED VIEW iceberg_mv
PARTITION BY dt
REFRESH DEFERRED MANUAL -- Or ASYNC
PROPERTIES (
    "refresh_mode" = "AUTO"
)
AS 
SELECT ... FROM iceberg_catalog.db.table;

Key prerequisites for

AUTO

mode: * Table Type: Currently only supported for Iceberg and Paimon tables. * Data Operations: The base table must be append-only. If StarRocks detects

UPDATE

,

DELETE

, or

OVERWRITE

operations, an

AUTO

MV will typically fall back to

PCT

(partition-level) refresh. * Default Mode: You can check or change the global default via the FE configuration

default_mv_refresh_mode

(default is

pct

). Recommended Next Steps: If you are definitely on 4.1.1 and the

CREATE

statement still fails with that specific error, it is possible that the

AUTO

mode was temporarily restricted in your specific build due to the identified rewrite/correctness issues. You can try setting it to

INCREMENTAL

to see if that is accepted; if

INCREMENTAL

works but

AUTO

doesn't, it confirms a validation restriction in that patch. For the most up-to-date status on when

AUTO

(and query rewrite for it) will be fully re-enabled, it is best to check the StarRocks GitHub Issues or ask in the community Slack. References • administration/management/FE_configuration.md

That's exactly what I am talking about - issue is on create - created an issue ticket for that https://github.com/StarRocks/starrocks/issues/75306