[OPENJPA-2449] refresh(PESSIMISTIC_WRITE) generates seperate SQL for the lock

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.1.2, 2.2.1.1, 2.2.3, 2.3.0, 2.4.0
• Fix Version/s: 2.1.2, 2.2.1.1, 2.2.3, 2.4.0
• Component/s: jdbc, kernel
• Patch Info: Patch Available
• Assignee: Heath Thomann
• Reporter: Albert Lee
• Created: 05/Nov/13 18:31
• Updated: 21/Sep/16 20:17
• Resolved: 06/Nov/13 03:43

Description

Simple refresh(PESSIMISTIC_WRITE) generates multiple SQL statements. E.g.

em.refresh(t1, LockModeType.PESSIMISTIC_WRITE);
//SELECT t0.CMLT_FOLDER_CONTEXT_UPDATE_TMS, t0.CRE_TIME FROM T1 t0 WHERE t0.c1 = ? [params=(String) c1]
//SELECT t0.c1 FROM T1 t0 WHERE t0.c1 = ? FOR READ ONLY WITH RR USE AND KEEP UPDATE LOCKS [params=(String) c1]

It would be nice if a single SQL is executed to optimize SQL execution and chances that another thread may compete to lock the same row.

Issue Links

• breaks: OPENJPA-2547 When two threads attempt to get a Pessimistic Lock, one thread gets a 'false' lock.