Cdap e2e framework update

[vedanshugarg04]

No description provided.

[google-cla]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

[gemini-code-assist]

Code Review

This pull request introduces significant updates across multiple database plugins, including the addition of transaction isolation level support, enhanced error reporting with external documentation links, and the implementation of upsert operations for Oracle. It also refactors the core database commons to improve connection management through task-level commit logic. Review feedback highlights critical issues, including a reference to an undefined variable in the Oracle plugin, potential SQL syntax errors when constructing upsert queries, and incorrect argument ordering in error message formatting.

[gemini-code-assist]

The externalDocumentationLink is not included in the formatted error message, even though it is checked for presence on line 322. Additionally, the arguments in String.format appear to be incorrect (swapped) compared to the implementation in AbstractDBSource, which will lead to a confusing error summary.

Suggested change

	errorMessage = String.format("%s For more details, see %s", errorMessageWithDetails, errorMessage);
	errorMessage = String.format("%s For more details, see %s", errorMessage, externalDocumentationLink);

[gemini-code-assist]

If all columns in fieldNames are also present in listKeys, the UPDATE SET clause will be empty, which results in invalid Oracle SQL syntax for the MERGE statement. The WHEN MATCHED clause should only be appended if there are non-key columns to update. Additionally, the nested loop for key lookup is inefficient ($O(N \times M)$); using a Set for lookups is recommended.

Suggested change

	boolean firstUpdateColumn = true;
	for (String fieldName : fieldNames) {
	boolean isKeyColumn = false;
	for (String listKey : listKeys) {
	String listKeyNoQuote = listKey.replace("\"", "");
	if (listKeyNoQuote.equals(fieldName)) {
	isKeyColumn = true;
	break;
	}
	}
	if (!isKeyColumn) {
	if (!firstUpdateColumn) {
	query.append(", ");
	}
	query.append("target.").append(fieldName).append(" = source.").append(fieldName);
	firstUpdateColumn = false;
	}
	}
	StringBuilder updateClause = new StringBuilder();
	boolean firstUpdateColumn = true;
	java.util.Set<String> keySet = new java.util.HashSet<>();
	for (String listKey : listKeys) {
	keySet.add(listKey.replace("\"", ""));
	}
	for (String fieldName : fieldNames) {
	if (!keySet.contains(fieldName)) {
	if (!firstUpdateColumn) {
	updateClause.append(", ");
	}
	updateClause.append("target.").append(fieldName).append(" = source.").append(fieldName);
	firstUpdateColumn = false;
	}
	}
	if (!firstUpdateColumn) {
	query.append("WHEN MATCHED THEN UPDATE SET ").append(updateClause).append(" ");
	}

[gemini-code-assist]

The variable modifiableColumnTypes is used but does not appear to be defined in this class or its parent. It should likely be columnTypes, which is the field used in the previous version of the code and in OracleSinkDBRecord. If a modifiable version was intended, ensure it is properly declared and initialized.

Suggested change

	int sqlType = modifiableColumnTypes.get(fieldIndex).getType();
	int sqlType = columnTypes.get(fieldIndex).getType();