| Jobson Martins 2006-01-26, 4:56 pm |
| Hi,
We have a Sales Force Automation application which is developed in
AppForge (PocketPC) using Ultralite for data storage and retrieval.
Two months ago, we deployed a "pilot" with 20 "production" users
and after nearly one month of operation we started to get
SQLE_MEMORY_ERROR and SQLE_TOO_MANY_TEMP_T
ABLES errors followed by
database corruption. Until now, half the users have already had this
problem.
We've used the Ultralite Interactive SQL tool (ulisql) to analyze the
corrupted databases. The severity of the corruption varies in each
case:
- ulisql can't even open the UDB file (-954 error);
- several rows with zero values in all fields (one specific table),
scattered all along the table;
- ulisql aborts when accessing one specific table (select * from
[table]);
- strange data (other table's name, other field's data, negative
values, etc) in some fields of the last 5 or 6 rows of one specific
table.
Here are some important facts about the problem:
- Ultralite version 9.0.2.3044 (ulmvb9.dll, UltraLite database for
MobileVB (TLS CE_300_ARM));
- Appforge CrossFire 5.6.1;
- PocketPC HP iPaq rz1710, with 32 MB (typically 5 or 6 MB of total
free memory when using our application);
- The typical UDB file size is 3 to 4 MB when the corruption happens;
- From time to time, a backup routine is executed inside the
application (not simultaneously with the other tasks the application is
doing). This routine copies the UDB file to a non volatile memory
location (in this specific case: "\iPaq File Store");
- The typical user tends to leave the application running in the PDA
for several days without exiting it (we have experienced a drop in the
number of new database corruption cases after we've advised the users
to exit the application at the end of every day);
- After the database corruption, the AppForge application aborts each
time it tries to access some corrupted data;
- In some cases both errors (SQLE_MEMORY_ERROR and
SQLE_TOO_MANY_TEMP_T
ABLES) have occurred, but in most of the cases only
the SQLE_MEMORY_ERROR.
We're still trying to reproduce the problem, but until now without any
success. Does anybody have experienced something similar? What are the
typical conditions on which this kind of error usually happens
(SQLE_MEMORY_ERROR and SQLE_TOO_MANY_TEMP_T
ABLES)? Unfortunately we
don't have any further details about the occurrence of the error
other than the error name. I appreciate any help.
Best Regards,
Jobson Martins
|