DRILL-8542: Support Paimon Format Plugin

[letian-jiang]

DRILL-8542: Support Paimon format plugin

Description

Introduce a Paimon format plugin, enabling Drill users to query Paimon tables directly via filesystem paths.

• support reading data from Paimon tables in Parquet and ORC formats
• support projection/filter/limit pushdown
• support snapshot read via table() with snapshotId or snapshotAsOfTime
• support metadata tables: #snapshots, #schemas, #files, #manifests

Usage examples:

• SELECT * FROM dfs./path/to/paimon_table
• SELECT * FROM table(dfs./path/to/paimon_table, snapshotId => 123)
• SELECT * FROM table(dfs./path/to/paimon_table, snapshotAsOfTime => 1700000000000)
• SELECT * FROM dfs./path/to/paimon_table#snapshots

Reference:

• https://paimon.apache.org/docs

[cgivre]

@letian-jiang
Thank you very much for this submission. I did a quick first pass and overall it looks good.

General comments:

1. You're overriding a lot of methods that I don't think actually need to be overridden. If the methods are not doing anything, I would suggest removing them.
2. Again, thank you for providing robust unit tests. However, I made some refactoring suggestions for this class.
3. Please avoid the x ? y : z notation for complex logic.
4. For non-obvious functions, please add some documentation. We don't need docstrings for getters/setters and other obvious code, but most people working on Drill are likely unfamiliar with Paimon, so any help you could give in the code is greatly appreciated.

[cgivre]

Nit: Please add blank line at the end of classes. Here and elsewhere.

[letian-jiang]

I believe I have addressed all the review comments. Could you please take another look? @cgivre

[cgivre]

Please add new line at the end of all classes. Here and elsewhere..

[cgivre]

Note: This is using the older version of the ManagedReader class. Please use org.apache.drill.exec.physical.impl.scan.v3.ManagedReader. This will require refactoring this class a bit.

[cgivre]

Looking good. Can you please add a SerDe test? If this test fails, you won't be able to update the config. Take a look here as an example. :

drill/contrib/format-excel/src/test/java/org/apache/drill/exec/store/excel/TestExcelFormat.java

Lines 564 to 570 in bcb4386

	public void testSerDe() throws Exception {
	String sql = "SELECT COUNT(*) as cnt FROM table(cp.`excel/test_data.xlsx` (type=> 'excel', sheetName => 'inconsistentData', allTextMode => true))";
	String plan = queryBuilder().sql(sql).explainJson();
	long cnt = queryBuilder().physical(plan).singletonLong();
	assertEquals("Counts should match",4L, cnt);
	}