[Enhancement]: Add dynamic configuration for lower_case_table_names i…

[hnwyllmm]

Task Description

Fix hardcoded table names in SQL queries to support lower_case_table_names system variable. This resolves issues where system tables cannot be found when lower_case_table_names=0 (case-sensitive mode) is configured.

Related to case-sensitivity handling for MySQL compatibility.

Solution Description

1. Replace hardcoded table names with constants: Changed direct string literals like __all_server and __all_zone to use constants from ob_inner_table_schema_constants.h (e.g., OB_ALL_SERVER_TNAME, OB_ALL_ZONE_TNAME)

2. Read lower_case_table_names from system variables: Modified bootstrap and schema initialization code to dynamically read the lower_case_table_names setting instead of hardcoding OB_LOWERCASE_AND_INSENSITIVE

3. Support environment variable configuration: Added support for setting lower_case_table_names via the LOWER_CASE_TABLE_NAMES environment variable in main.cpp

4. Set proper name_case_mode for system tables: Ensured system tables always use case-sensitive mode (OB_ORIGIN_AND_SENSITIVE) regardless of tenant settings, while user tables respect the tenant's lower_case_table_names configuration

Modified files:

• src/observer/main.cpp
• src/rootserver/ob_bootstrap.cpp
• src/share/ob_locality_table_operator.cpp
• src/share/schema/ob_schema_mgr.cpp
• src/share/schema/ob_schema_utils.cpp
• src/share/schema/ob_server_schema_service.cpp
• src/storage/tx/wrs/ob_tenant_weak_read_cluster_service.cpp

Passed Regressions

• Manually tested with lower_case_table_names=0 configuration
• Verified system tables are accessible with case-sensitive mode
• Confirmed bootstrap process completes successfully
• Tested SQL queries against system tables work correctly
• After making the modifications, I rebuilt and mirrored the image for running. Then, I added an environment variable to the Docker configuration to pull up the container. After verifying the settings and querying the configuration, I found that the parameter was effective

Upgrade Compatibility

This change is backward compatible:

• Default behavior remains unchanged (defaults to lower_case_table_names=1)
• Existing deployments will continue to work without modification
• New configuration option is opt-in via environment variable or command-line parameter

Other Information

This fix improves MySQL compatibility by properly supporting the lower_case_table_names system variable, which is important for:

• Cross-platform deployments (Linux/macOS/Windows)
• Migration from MySQL databases with case-sensitive table names
• Compliance with MySQL standard behavior

Release Note

Enhancement: Added proper support for lower_case_table_names system variable. System table names are now referenced using constants instead of hardcoded strings, enabling case-sensitive table name mode (lower_case_table_names=0) to work correctly. This improves MySQL compatibility and supports cross-platform deployments.