Hi, everyone,
I’d like to initiate a discussion on FLIP-492: Support Query Modifications
for Materialized Tables[1].
In FLIP-435[2], we introduced *MATERIALIZED TABLES*. By defining query
logic and specifying data freshness requirements, users can efficiently
build data pipelines, greatly improving development productivity.
FLIP-492 builds on this by addressing a common need: the ability to modify
the query logic of an existing MATERIALIZED TABLE. Two approaches are
proposed:
*1. Modifying the Query Logic: ALTER MATERIALIZED TABLE AS <query>*
Retain historical data while modifying the query logic:
```
ALTER MATERIALIZED TABLE [catalog_name.][db_name.]table_name AS <query>
```
*2. Replacing the Table: CREATE OR REPLACE MATERIALIZED TABLE*
Reconstruct the table with a new query, discarding all historical data:
```
CREATE [OR REPLACE] MATERIALIZED TABLE [catalog_name.][db_name.]table_name
[ ([<table_constraint>]) ]
[COMMENT table_comment]
[PARTITIONED BY (partition_column_name1, partition_column_name2, ...)]
[WITH (key1=val1, key2=val2, ...)]
FRESHNESS = INTERVAL '<num>' { SECOND | MINUTE | HOUR | DAY }
[REFRESH_MODE = { CONTINUOUS | FULL }]
AS <select_statement>
```
For a more detailed explanation of this proposal, please refer to the
FLIP-492[1] documentation.
Your feedback and suggestions are highly appreciated to help refine this
proposal further.
Lastly, I’d like to thank Ron and Lincoln (cc’d) for their valuable input
and suggestions during the drafting process.
Looking forward to hearing your thoughts!
Best,
Feng Jin
[1].
https://cwiki.apache.org/confluence/display/FLINK/FLIP-492%3A+Support+Query+Modifications+for+Materialized+Tables
[2].
https://cwiki.apache.org/confluence/display/FLINK/FLIP-435%3A+Introduce+a+New+Materialized+Table+for+Simplifying+Data+Pipelines
