gen-pack

Generates a complete SQL migration pack that includes both schema changes (DDL) and data changes (DML). This is the main output artifact of DeepDiff DB — a single, reviewable SQL file ready to apply to production.

Usage

deepdiffdb gen-pack --config deepdiffdb.config.yaml

What It Generates

The migration pack is a single transactional SQL file containing:

• Schema DDL — ALTER TABLE, CREATE TABLE, CREATE INDEX, ADD CONSTRAINT statements for schema differences
• Data DML — DELETE + INSERT pairs (or UPDATE) for each changed row, batched in groups of 1000
• Foreign key management — Driver-specific statements to disable FK checks before data changes and re-enable them after (e.g., SET FOREIGN_KEY_CHECKS=0 for MySQL, DISABLE CONSTRAINT ALL for Oracle)
• Everything wrapped in a single BEGIN / COMMIT transaction

gen-pack internally runs the same diff logic as diff, so you always get a fresh pack based on the current state of both databases.

Flags

Flag	Description
--config	Path to the configuration file (default: deepdiffdb.config.yaml)
--html	Generate an interactive HTML report (report.html)
--batch-size N	Rows per keyset-paginated query (overrides performance.hash_batch_size)
--parallel N	Max tables hashed concurrently (overrides performance.max_parallel_tables)
--resume	Resume from the last saved checkpoint
--verbose	Enable debug-level logging
--log-level	Minimum log level: debug, info, warn, error (default: info)
--log-format	Log output format: text or json (default: text)
--log-file	Write logs to this file in addition to stdout

Output Files

File	Description
schema_diff.json	Schema differences (informational; schema drift emits warnings but does not block)
content_diff.json	Row-level differences
conflicts.json	Conflict details
summary.txt	Summary statistics
resolutions_summary.json	Resolution statistics (when conflict resolutions exist)
migration_pack.sql	The complete, transactional migration script
report.html	Interactive HTML report (only when --html is used)

Example

# Standard pack generation
deepdiffdb gen-pack --config deepdiffdb.config.yaml

# With HTML report and parallelism for large databases
deepdiffdb gen-pack --config deepdiffdb.config.yaml --html --batch-size 5000 --parallel 4

# Resume a previously interrupted gen-pack
deepdiffdb gen-pack --config deepdiffdb.config.yaml --resume

Schema Drift Behaviour

Unlike diff, gen-pack does not abort on schema drift. It emits warnings for tables with schema differences and skips data diffing on those tables. Tables with matching schemas are processed normally. This lets you generate a pack that handles both the schema migration and data migration in a single file.

Resuming Interrupted Runs

If a gen-pack run is interrupted (network failure, process kill), restart with --resume:

deepdiffdb gen-pack --config deepdiffdb.config.yaml --resume

DeepDiff DB loads the last checkpoint and continues from where it left off. Checkpoints expire after 24 hours. See Checkpoint and Resume for details.