Database Certification

The JADE Database utility Operation menu Certify Files command and the JADE Database Administration utility certify file or partition action enables you to perform a read‑only check on the integrity of your database files. The database certification operation verifies the physical integrity of your database files. This process involves a series of scans that verify the contents of records and perform consistency cross‑checks.

The certification of a database file involves three distinct phases or passes. A summary of the certification process, including statistics on the number of instances of objects and subobjects found in each scanned class and any errors that are detected, is reported to your certify.log. The log file output is prefixed with process‑id‑thread‑id; for example:

04230-1850 2017/03/15 13:35:12.043 Certification of file: _userscm [31] commenced

You can perform certifications of multiple files of a database in parallel. This capability does not utilize worker threads within JADE; the approach taken supports multiple processes accessing the same database, where each process is certifying a different file or list of files. (A sharing access violation will occur if a certify process attempts to certify a file already being certified by another certify process.)

The JADE Database utility performs the following passes to certify your database files.

  1. The file is read sequentially. The following table lists the verification performed for each block type during the sequential read.

    Verify Verifies…
    Fixed Data Block Block slot content and block meta data are valid and consistent
    Head Block Type and length are valid
    Tail Block Block content (types and lengths) are valid

    As objects are encountered during block analysis, the corresponding index entry is retrieved and the file addresses matched.

  2. The indexes are traversed in object identifier (oid) order. Consistency checks are performed on the indexes as each index block is read (for example, a check for illegal duplicates and that keys occur in the correct sequence).

    For each object found in the indexes, the target object record is retrieved and the index and object record keys are compared for equality.

For details, see "Using the Certify Files Command", in Chapter 1, and "Certify", in Chapter 2.