Question

Is the $HVR_CONFIG directory just for log files? How much disk space is recommended?

Answer

Disk space in the $HVR_CONFIG directory is used for several purposes:

On the Hub-machine

1. Storage of Local Data Processing logfiles (growing, but managed by hvrmaint)
2. The temporary storage of transaction files.
   1. The capture job reads all the changes, compresses them, and sends them to the hub-machine
   2. These files are immediately picked up by the integrate job and deleted when the changes are applied to the target database.

Normally there are 0 or 1 files (per channel). However when the integrate job is stopped (crashed or suspended), these files are starting to pile up. The growth of disk space can be estimated: as the amount of Ingres journal / Oracle archive files that are generated (in a day) times the Local Data Processing compression ratio (typically 90 % or higher, but use 80 % to be safe). After a couple of days, you will decide to use Refresh to reinitialize the channel, instead of using the transaction files to process all the changes. So storage for a couple of days would suffice.

On the capture / integrate machine

During replication:

Spilling of big transactions that can not be held in memory, e.g. used with long data types (CLOB, etc.) or a single transaction that updates 1 million rows.

Estimated: the size of the/your biggest transaction * compression ratio

During row-wise refresh / compare: for sorting tables.

Estimated: 3 * (size of the largest table) * (parallelism in compare or refresh)

Before HVR 4.6.2 files for case 2 (sorting during row-wise) are only compressed if HVR_SORT_COMPRESS=1 is set.

After HVR 4.6.2, temp files for cases 1, 2, 3, 4 & 5 are compressed unless $HVR_TMP_COMPRESS_LEVEL=0 is set.

After HVR 4.6.2 the estimate should

Estimated: 3 * (size of the largest table) * (parallelism in compare or refresh) * (compression ratio)