Japan's Financial Services Agency requires financial institutions to maintain accurate and complete records of transactions for specified retention periods. For a database-backed system, the most reliable way to satisfy this requirement is to archive the write-ahead log in a verifiable format, rather than relying on periodic backups or application-level export jobs.
What the WAL Contains and Why It Is the Right Archival Target ¶
The write-ahead log is the authoritative record of every change the database has made, in the order those changes occurred. It is written before any change is applied to the data files, which means it is complete even if the database crashes mid-operation. Archiving the WAL gives you a record that is more complete than a snapshot backup and more reliable than an application-level audit table, which can be modified by application code.
Hash Chain Verification ¶
Grit Core Lab's WAL archival includes a SHA-256 hash of each log segment, and each segment's hash incorporates the hash of the previous segment. This creates a hash chain that can be verified offline: if any segment has been modified after archival, the chain breaks at that point. For FSA reporting purposes, this provides evidence that the archived log has not been tampered with between the time of the transaction and the time of the audit.
Retention Configuration and Domestic Storage Providers ¶
WAL retention is configurable from 7 to 365 days. For most FSA-regulated workloads, a retention period of at least one year is appropriate. Grit Core Lab 3.2 added native support for Sakura Object Storage, which allows institutions that require data to remain on domestic Japanese infrastructure to archive the WAL without routing data through foreign cloud providers. The configuration requires a storage endpoint URL and an access key; no additional adapter is needed.
The compliance audit export tool, which produces structured reports from the archived WAL for FSA submission, is described in the full capability list. For questions about specific reporting requirements, reach us directly at contact@gritcorelab.com.