[Improve][Connector-V2] Support dynamic write mode for JDBC Sink

[rewerma]

Purpose of this pull request

Support dynamic write mode: sql, copy/copy_sql/merge/copy_merge for JDBC Sink

Does this PR introduce any user-facing change?

no

How was this patch tested?

exist e2e test.

Check list

• If any new Jar binary package adding in your PR, please add License Notice according
  New License Guide
• If necessary, please update the documentation to describe the new feature. https://github.com/apache/seatunnel/tree/dev/docs
• If you are contributing the connector code, please check that the following files are updated:
  1. Update plugin-mapping.properties and add new connector information in it
  2. Update the pom file of seatunnel-dist
  3. Add ci label in label-scope-conf
  4. Add e2e testcase in seatunnel-e2e
  5. Update connector plugin_config
• Update the release-note.

[Copilot]

Pull Request Overview

This PR adds support for dynamic write modes (SQL, COPY, COPY_SQL, MERGE, COPY_MERGE) for the JDBC Sink and updates related logic for temporary tables, configuration options, and documentation. Key changes include:

• Enhancements to the sink implementation (e.g., DynamicBufferedBatchStatementExecutor) to support merge operations via temporary tables.
• Updates to configuration options and JDBC dialects (e.g., PostgresDialect) to incorporate the new write modes.
• Modifications to e2e tests and documentation to reflect the new functionality.

Reviewed Changes

Copilot reviewed 20 out of 21 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
seatunnel-e2e/.../JdbcPostgresIT.java	Updated test configuration files and enhanced error messages with stderr output.
seatunnel-connectors-v2/connector-jdbc/sink/savemode/JdbcSaveModeHandler.java	Modified to accept temporary table parameters and update schema creation accordingly.
seatunnel-connectors-v2/connector-jdbc/sink/JdbcSinkFactory.java & JdbcSink.java	Added handling for new write modes and temporary table logic in sink creation.
seatunnel-connectors-v2/connector-jdbc/internal/executor/DynamicBufferedBatchStatementExecutor.java	New executor supports dynamic buffering and merge operations using a temporary table.
seatunnel-connectors-v2/connector-jdbc/internal/dialect/psql/PostgresDialect.java	Extended to provide a merge statement for PostgreSQL dialect.
seatunnel-connectors-v2/connector-jdbc/internal/dialect/psql/PostgresCopyBatchStatementExecutor.java	Updated CSV handling and copy command preparation for the new write modes.
Various config and documentation files	Added new options (write_mode, temp_table_name, temp_column_batch_code, temp_column_row_kind) and updated documentation accordingly.

Files not reviewed (1)

• seatunnel-e2e/seatunnel-connector-v2-e2e/connector-jdbc-e2e/connector-jdbc-e2e-part-3/src/test/resources/jdbc_postgres_source_and_sink_copy.conf: Language not supported

Comments suppressed due to low confidence (2)

seatunnel-connectors-v2/connector-jdbc/src/main/java/org/apache/seatunnel/connectors/seatunnel/jdbc/internal/executor/DynamicBufferedBatchStatementExecutor.java:242

• [nitpick] The variable name 'pariRow' appears to be a typo. Consider renaming it to 'pair' or 'rowPair' for improved clarity.

for (Pair<Boolean, SeaTunnelRow> pariRow : buffer.values()) {

seatunnel-connectors-v2/connector-jdbc/src/main/java/org/apache/seatunnel/connectors/seatunnel/jdbc/internal/dialect/psql/PostgresDialect.java:210

• If 'updateClause' is empty, the generated MERGE statement may be invalid. Consider handling this case (for example, by using 'DO NOTHING') when there is nothing to update.

String mergeSQL = String.format("%s ON CONFLICT (%s) DO UPDATE SET %s", insertIntoBySQLStatement, uniqueColumns, updateClause);