Weird TT6003 error

Question

Hi,
Cache Group:
CREATE DYNAMIC ASYNCHRONOUS WRITETHROUGH CACHE GROUP SUBSCRIBER_CACHE_GROUP
FROM SUBSCRIBER
     ID NUMBER(30) NOT NULL ,
     PRIMARY KEY(ID)
DEVICE
     ID NUMBER(30) NOT NULL ,
     SUBSCRIBERID NUMBER(30) NULL ,
     PRIMARY KEY(ID),
     FOREIGN KEY(SUBSCRIBERID) REFERENCES SUBSCRIBER(ID)
DEVICEIDENTIFIER
     ID NUMBER(30) NOT NULL ,
     DEVICEID NUMBER(30) NULL ,
     PRIMARY KEY(ID),
     FOREIGN KEY(DEVICEID) REFERENCES DEVICE(ID)
View:
CREATE VIEW SUBSCRIPTIONIDENTIFIER ( ID,SUBSCRIBERID,GROUPNAME,IDENTIFIERTYPE,IDENTIFIERVALUE,SIID )
     AS SELECT DI.ID,DE.SUBSCRIBERID,DE.GROUPNAME,DI.IDENTIFIERTYPE,DI.IDENTIFIERVALUE,DE.ID
          FROM DEVICE de, DEVICEIDENTIFIER di
          WHERE de.id=di.deviceid;
One error is found in our test environment.
java.sql.SQLException: [TimesTen][TimesTen 11.2.1.4.0 ODBC Driver][TimesTen]TT6003: Lock request denied because of time-out
Details: Tran 143.23106 (pid 19946) wants Sn lock on rowid BMUFVUAAAAxogAALDp, table SUBSCRIBER. But tran 144.67398 (pid 19946) has it in Xn (request was Xn). Holder SQL (select ID,identifierType,identifiervalue,subscriberId,groupName,siid from subscriptionidentifie...) -- file "tindex.c", lineno 4277, procedure "sbTixNext()"
Whole query SQL is "select ID,identifierType,identifier value,subscriberId,groupName,siid from subscriptionidentifier where subscriberId =?".
My questions are:
1. Why does select sql place Xn lock on one row?
2. What and when operations may place Sn lock on one row? It seems that select will not place Sn lock because Xn doesn't block read as I know.
3. This is almost all information I can provide, and is there any tool which can be used for timesten trace in test environment?
Regards,
Nesta

Answer 1

I think you are referring to the lockwait timeout (default is 10 seconds as you mentioned)
you can change this within a connection, here is an example of increasing that:
To indicate a 30 second lock wait, use:
CALL ttLockWait (30);
It can also be set as a dsn general connection attribute:
LockWait=30
btw, there is mention in the thread about how this timeout acts:
by Nesta: Does this mean that if data load from Oracle is less than 10s, there will be no such timeout lock?
by Chris: if the data load completes within this time you should not get a lock timeout message
The lockwait timeout is a timeout for how long it waits to try to get a lock before it gives up and returns 6003
In the case asked above it probably does mean that the lock is being held for > 10 s, but it may not necesarilly
mean it only occurs because of the data load is taking > 10 s, I think its possible that if multiple things are
trying to get this lock, e.g. if connection A, B, and C want it, A has it first for 6 seconds, B and C are waiting, if B gets its
and holds it for another 6 seconds, C will get the lockwait timeout 6003, when 10 seconds elapsed, even thought
it only takes 6 seconds for the load. I don't think that when the lock comes free that the lockwait gets reset for C.
I just want to make sure its understood that its because its waiting for the lock, not necessarily tied to how
long it takes to load.
Jim