[DERBY-3601] Optimize LOBStateTracker for non-locator servers

• Type: Improvement
• Status: Closed
• Priority: Trivial
• Resolution: Fixed
• Affects Version/s: 10.4.1.3, 10.5.1.1
• Fix Version/s: 10.4.2.1, 10.5.1.1
• Component/s: Network Client
• Assignee: Kristian Waagan
• Reporter: Kristian Waagan
• Created: 07/Apr/08 10:38
• Updated: 29/Jun/09 13:13
• Resolved: 02/Oct/08 15:30

Description

The following comments posted for DERBY-3571 should be addressed if we choose to allow multiple calls to the various getter methods on LOB columns, except for the getter methods returning streams:
----- Knut Anders wrote:
've tried out the 2a patch and it seems to work as intended. My only nits are:

• LOBStateTracker.checkCurrentRow(): couldn't Arrays.fill() be moved inside the if block?
• should discardState() and markAccessed() check the release flag?
• should ResultSet.createLOBColumnTracker() use LOBStateTracker.NO_OP_TRACKER instead of allocating a new when serverSupportsLocators() returns false?

  ---

Note that it is a requirement that we allow multiple calls to the getter methods, otherwise we need to maintain the state for non-locator LOB columns as well to track the number of accesses. Another options is to rely on a different mechanism to track accesses.

Issue Links

• is related to: DERBY-3571 LOB locators are not released if the LOB columns are not accessed by the client