Sybase 12.4.2 manual Saving memory, Data compression, Decrease buffer cache settings

CHAPTER 12 Managing System Resources

Table 12-3: Default block sizes
Page Size (KB)	Block Size (bytes)
64	4096
128	8192
256	16384
512	32768

Data compression

Adaptive Server IQ compresses all data when storing it on disk. Data compression both reduces disk space requirements and contributes to performance. The amount of compression is determined automatically, based on the IQ page size.

Saving memory

If your machine does not have enough memory, to save memory you can try the following adjustments.

Decrease buffer cache settings

You may be able to save memory by decreasing buffer cache sizes. Keep in mind that if you decrease the buffer caches too much, you could make your data loads or queries inefficient or incomplete due to insufficient buffers.

Decrease memory used for loads

You can set the LOAD_MEMORY_MB option to limit the amount of heap memory used for loads and other similar operations. See “Memory for loads, synchronizations, and deletions” on page 421.

Adjust blocking factor for loads

Use BLOCK FACTOR to reduce I/O when loading from a flat file. The BLOCK FACTOR option of the LOAD command specifies the blocking factor, or number of records per block, that were used when the input file was created. The default BLOCK FACTOR is 10,000.

The syntax for this load option is as follows:

BLOCK FACTOR = integer

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