We can get rid of the all of the tests but your spark + flink test

This is a good test for writing the equality delete using the stream execution environment! I'd also suggest creating a test for an UPSERT case by leveraging the FlinkTableEnviroment. This will help you see how, the UPSERT leverages an equality delete to replace the value.

You can add a test to TestFlinkCatalogTable.java like this:

    sql("CREATE TABLE test_table (id INT, data STRING, PRIMARY KEY(id) NOT ENFORCED) WITH ('format-version'='2', 'write.upsert.enabled'='true')");

    sql("INSERT INTO test_table VALUES (1, 'a'), (2, 'b'), (3, 'c')");

    // Perform upsert operation
    sql("INSERT INTO test_table VALUES (2, 'updated_b'), (4, 'd')");

To expand upon this, I'd suggest adding some DeleteFile assertions. For example, what do you expect the DeleteFile to look like we want to delete based on:

• one column: id = 1
• all columns: id = 1 and data = 'a'
• range: id > 3 (also how does flink get the values greater than 3?)

We should set the same warehouse as the Flink catalog to ensure we are using the same tables.

spark = SparkSession.builder()
        .appName("iceberg-spark")
        .master("local[*]")
        .config("spark.sql.catalog.hadoop_catalog", "org.apache.iceberg.spark.SparkCatalog")
        .config("spark.sql.catalog.hadoop_catalog.type", "hadoop")
        .config("spark.sql.catalog.hadoop_catalog.warehouse", CATALOG_EXTENSION.warehouse())
        .getOrCreate();