[AUXWODBC], [ORACLE], [SYBASE]
use_checksum=0
0 means switched off, 1 means switched on.
use_checksum is a record locking and contention control mechanism for SQL databases. The ADC takes a checksum of all the data records read from the SQL database and stores this within the timestamp field of the DP4 data record structure.
When the user subsequently attempts to update this record, the ADC sends off a 'SELECT ... FOR UPDATE' to lock the record. This also reads the record, for which another checksum is taken and compared with the original checksum to determine whether the data record has been altered since the user first read the record and hence whether there is possible data loss due to the record having been updated by another user.
Although the default for this value is 0 you are strongly recommended to set it to 1 as otherwise contention errors may well not be detected.