11.17.2 Timing for reorganizing a system table

To avoid the shortage of free disk space due to increase of invalid row data, you need to execute the adbreorgsystemdata command to reorganize a system table (base table).

The timing for reorganizing a system table (base table) differs, depending on whether the system-table DB area file is created by using a regular file or block special file.

▪ When using a regular file

If the free disk space for storing a system table (base table) becomes insufficient due to increase of invalid row data, no warning message is output from the HADB server.

Therefore, before you start operations, consider and determine the timing for reorganizing the system table (base table) by the following procedure. Then, after you start operations, reorganize the system table (base table) at the timing you determined.

Note

When a block special file is used, warning messages are output from the HADB server at the timing reorganization is required. Therefore, we recommend that you use a block special file when creating a system-table DB area file. For details about the procedure for changing a regular file to a block special file, see (1) Changing a data DB area file from a regular file to a block special file in 11.10.5 Changing the storage location of data DB area files.

Procedure:

1. Determine the frequency of reorganizing a system table (base table).

   Execute the adbreorgsystemdata command to determine the frequency of reorganizing a system table (base table). The basic guideline is every six months.

2. Estimate the size of the system-table DB area.

   Estimate the size of the system-table DB area based on the frequency of reorganization that you determined in step 1. For details about estimation, see 5.12 Estimating the size of the system-table DB area.

3. Create a database based on the estimation result.

   Based on the size of system-table DB area that you determined in step 2, prepare a disk and create a database.

4. Regularly reorganize the system table (base table).

   After you start operations, based on the frequency of reorganization that you determined in step 1, execute the adbreorgsystemdata command.

▪ When using a block special file

If the free disk space for storing a system table (base table) becomes insufficient due to increase of invalid row data, the following warning messages are output from the HADB server:

• KFAA61213-W message

• KFAA61214-W message

When the warning messages are output, execute the adbreorgsystemdata command to reorganize the system table (base table).

Note that there is no problem if you reorganize a system table (base table) when it is suitable for your operations even if no warning message is output. In that case, we recommend that you execute the adbreorgsystemdata command about every six months.

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