Memory Use in the Server

Optimizing Memory Usage for Faster Response Times

If all the files an application needs at any given time could be stored in memory, response times would be significantly faster. Accessing main memory is much quicker than using disk input/output (I/O) because disk access times are much longer. However, in practice, it is impossible to keep everything in memory, especially if a database contains millions of records.

Efficient Data Transfer Between Memory and Disk

During an application session, much of the data must be continually transferred between memory and disk. This includes data stored in the database, database definitions, screen definitions, and application programs.

Controlling Data Locks

Maximizing disk access is crucial, but so is controlling locks over the data being processed by each user once it is available in memory. This topic is discussed in detail in the Locks and Deadlocks Conditions section.

Zim Server Efficiency

Zim Server’s efficiency relies heavily on the available memory allocated for its use. When Zim Server starts, it reads its configuration file, calculates the required memory, and allocates the corresponding shared memory for client connections.

Shared Memory Allocation

Shared memory is allocated using a mapping mechanism that associates an address space with physical memory. If the available real memory is sufficient to accommodate the allocated shared memory, Zim Server operations will be highly efficient. If not, the operating system will need to swap out and swap in portions of shared memory that do not fit in the real memory.

Impact of Swap Operations

Although swap operations are faster than regular file operations, they are still slower than real memory operations. Therefore, administrators must consider this factor when configuring Zim Server.

Configuration Options for Efficiency

All Zim Server configuration options address efficiency issues. Key options include Checkpoint Buffers, Checkpoint Transactions, Clustered Commits, Maximum Blocks per User, and Maximum Data Blocks.