preview_command
Preview the exact database migration command that will be executed, preventing unintended changes by verifying parameters before running.
Instructions
Build and preview a MigratorXpress CLI command WITHOUT executing it. This shows the exact command that will be run. Use this FIRST before executing any command. License text is masked in the display output.
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| auth_file | Yes | Path to authentication/credentials JSON file | |
| source_db_auth_id | Yes | Source database credential ID from the auth file | |
| source_db_name | Yes | Source database name to migrate from | |
| target_db_auth_id | Yes | Target database credential ID from the auth file | |
| target_db_name | Yes | Target database name to migrate to | |
| migration_db_auth_id | Yes | Migration tracking database credential ID from the auth file | |
| source_schema_name | No | Source schema name. If omitted, all schemas are migrated | |
| target_schema_name | No | Target schema name. Defaults to source schema name if omitted | |
| task_list | No | Tasks to run (e.g., translate, create, transfer, diff, copy_pk, copy_ak, copy_fk, all) | |
| resume | No | Resume a previous run by RUN_ID | |
| fasttransfer_dir_path | No | Path to FastTransfer binary directory for parallel data transfer | |
| fasttransfer_p | No | FastTransfer parallel degree (number of threads per table transfer) | |
| ft_large_table_th | No | Row count threshold above which FastTransfer parallelism is used | |
| n_jobs | No | Number of concurrent table transfers | |
| cci_threshold | No | Row count threshold for clustered columnstore index creation on target | |
| aci_threshold | No | Row count threshold for auto-created indexes on target | |
| migration_db_mode | No | Migration database mode: preserve (keep), truncate (clear data), drop (recreate) | |
| compute_nbrows | No | Compute row counts for source tables before transfer | |
| drop_tables_if_exists | No | Drop target tables before creating them | |
| load_mode | No | Data load mode: truncate (clear target first) or append | |
| include_tables | No | Table include patterns, comma-separated. Supports wildcards | |
| exclude_tables | No | Table exclude patterns, comma-separated. Supports wildcards | |
| min_rows | No | Minimum row count filter — only migrate tables with at least this many rows | |
| max_rows | No | Maximum row count filter — only migrate tables with at most this many rows | |
| forced_int_id_prefixes | No | Column name prefixes to force integer identity mapping | |
| forced_int_id_suffixes | No | Column name suffixes to force integer identity mapping | |
| profiling_sample_pc | No | Percentage of rows to sample for data profiling (0-100) | |
| p_query | No | Parallelism degree for profiling queries | |
| min_sample_pc_profile | No | Minimum sample percentage for profiling small tables | |
| force | No | Force overwrite of existing migration data | |
| basic_diff | No | Use basic diff mode (row counts only, no checksum) | |
| without_xid | No | Disable transaction ID tracking during transfer | |
| fk_mode | No | Foreign key mode: trusted, untrusted, or disabled | |
| log_level | No | Logging verbosity level | |
| log_dir | No | Directory for log files | |
| no_banner | No | Suppress the startup banner | |
| no_progress | No | Disable progress bar display | |
| quiet_ft | No | Suppress FastTransfer console output during data transfer | |
| license | No | License key (will be masked in display) | |
| license_file | No | Path to license key file | |
| os_type | No | Target operating system for command formatting | linux |