[OPENJPA-411] List.add(int,Object) is inefficient in default mappings

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 0.9.0, 0.9.6, 0.9.7, 1.0.0
• Assignee: Unassigned
• Reporter: Patrick Linskey
• Created: 22/Oct/07 21:33
• Updated: 16/Sep/08 18:59

Description

From [e-mail]:

When List.add(index, object) is being used
OpenJPA sends the following sql statement, so the order of the elements can
be built up from scratch:
"Delete from RELATION_TABLE where ID = ?"

In ms sql server this causes an exclusive lock on the entire table which of
course easily introduces blocking issues (long running transactions having a
shared lock or other client who like to insert objects in their list as
well).

List.add(Object) does not have this behaviour so when adding objects to the
end of the list it is always better to use this method.

Sub-Tasks

• Alternate algorithms for list order maintenance: Open