[DERBY-1677] Investigate increasing the memory limit that is used to calculate the sortbuffer size for sorting.

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 10.0.2.0, 10.0.2.1, 10.1.1.0, 10.1.2.1, 10.1.3.1, 10.2.1.6
• Component/s: Store
• Bug behavior facts: Performance
• Assignee: Unassigned
• Reporter: Sunitha Kambhampati
• Created: 11/Aug/06 19:19
• Updated: 29/Jun/09 14:32

Description

The sortbuffer is the in memory sort buffer and the size of the sort buffer is calculated using the default memory limit of 1M if derby.storage.sortBufferMax is not specified. .

This may not be appropriate for large systems. Investigate if we can up this value.

see org.apache.derby.impl.store.access.sort.ExternalSortFactory
protected static final int DEFAULT_MEM_USE = 1024*1024; // aim for about 1Meg
The calculations to come up with the initial size for sortbuffer is in ExternalSortFactory.createSort()

Issue Links

• relates to: DERBY-1661 Create index on large tables fails with too many open files , FileNotFoundException.
• relates to: DERBY-1676 Dynamically change the max merge runs in a merge phase during external sorting.
• relates to: DERBY-1679 Improve usage of file resources when sorting