8.4.1 Placing system RDAREAs

System RDAREAs should be placed taking into account the placement of user RDAREAs. Points to be considered when a system RDAREA is placed are discussed as follows.

A system RDAREA should not be placed on the same disk with user RDAREAs.

Among the system RDAREAs, data dictionary RDAREAs and data directory RDAREAs are accessed frequently by HiRDB for SQL statement analysis and other operations. If they are placed on the same disk as user RDAREAs, contention may occur between an access request for the purpose of SQL statement analysis and a table access request, in which case one of the requests will be placed on hold until the other request has been processed.

The following figure shows an example of system RDAREA placement that does not generate disk access contention.

Figure 8-5 Example of system RDAREA placement (HiRDB/Single Server)

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