Offline Snapshot Example

This example demonstrates how to save a database schema to a compressed offline snapshot file, and how to later reconnect to that snapshot as though it were a live database — without needing the original database to be running.

How to Run

Before running this example, complete the setup in Getting Started.

Create an offline snapshot from the live database. Run the command:

schemacrawler \
  --server postgresql \
  --host postgresql \
  --database schemacrawler \
  --user schemacrawler \
  --password schemacrawler \
  --info-level maximum \
  --command serialize \
  --output-format ser \
  --output-file share/offline.ser

This produces a compressed serialized snapshot file named “offline.ser”. For details on snapshot formats, limitations, and requirements, see SchemaCrawler Offline Catalog Snapshot.

When creating an offline database, prefer to use maximum info-level.

Use the offline snapshot — no live database connection required. Run the command:

schemacrawler \
  --server offline \
  --database share/offline.ser \
  --info-level standard \
  --command=schema

How to Experiment

Try other SchemaCrawler commands against the offline snapshot, such as list, brief, or details:

schemacrawler \
  --server offline \
  --database share/offline.ser \
  --info-level standard \
  --command details

Generate an HTML or text report from the offline snapshot:

schemacrawler \
  --server offline \
  --database share/offline.ser \
  --info-level standard \
  --command schema \
  --output-format html \
  --output-file share/output.html

Use the offline snapshot with the grep options to search metadata without a live connection:

schemacrawler \
  --server offline \
  --database share/offline.ser \
  --info-level standard \
  --command=details \
  --no-info \
  --grep-columns ".*\.publisher"

Use the offline snapshot with lint to find design issues without a live database:

schemacrawler \
  --server offline \
  --database share/offline.ser \
  --info-level standard \
  --command=lint