I have the following code:
Administratie__c theAdmin = [SELECT Artikelen_laatst_bijgewerkt_op__c FROM Administratie__c LIMIT 1][0];
theAdmin.Artikelen_laatst_bijgewerkt_op__c = dateTimeOfLastModification;
update theAdmin;
Which leads to the following log lines:
15:54:11.0 (23662906)|SOQL_EXECUTE_BEGIN|[19]|Aggregations:0|SELECT Artikelen_laatst_bijgewerkt_op__c FROM Administratie__c LIMIT 1
15:54:11.0 (26685794)|SOQL_EXECUTE_END|[19]|Rows:1
15:54:11.0 (26718836)|HEAP_ALLOCATE|[19]|Bytes:8
15:54:11.0 (26741000)|HEAP_ALLOCATE|[19]|Bytes:70
15:54:11.0 (26845854)|HEAP_ALLOCATE|[19]|Bytes:8
15:54:11.0 (26894245)|HEAP_ALLOCATE|[19]|Bytes:12
15:54:11.0 (26904321)|VARIABLE_SCOPE_BEGIN|[19]|theAdmin|Administratie__c|true|false
15:54:11.0 (26952408)|VARIABLE_ASSIGNMENT|[19]|theAdmin|{"Artikelen_laatst_bijgewerkt_op__c":"2019-03-28T13:48:14.000Z","Id":"a0G1l000000c12LEAQ"}|0x5dfa991c
15:54:11.0 (26960746)|STATEMENT_EXECUTE|[20]
15:54:11.0 (27028989)|VARIABLE_ASSIGNMENT|[20]|this.Artikelen_laatst_bijgewerkt_op__c|"2019-03-28T14:54:11.963Z"|0x5dfa991c
15:54:11.0 (27035931)|STATEMENT_EXECUTE|[21]
15:54:11.0 (27071056)|HEAP_ALLOCATE|[21]|Bytes:8
15:54:11.0 (27085877)|DML_BEGIN|[21]|Op:Update|Type:Administratie__c|Rows:1
15:54:11.0 (27118984)|HEAP_ALLOCATE|[EXTERNAL]|Bytes:8
15:54:11.0 (55148251)|DML_END|[21]
This suggests that the update was successful. But I also see this at the end of the log:
08:33:30.350 (350869114)|CUMULATIVE_LIMIT_USAGE
08:33:30.350 (350869114)|LIMIT_USAGE_FOR_NS|(default)|
Number of SOQL queries: 0 out of 200
Number of query rows: 0 out of 50000
Number of SOSL queries: 0 out of 20
Number of DML statements: 0 out of 150
Number of DML rows: 0 out of 10000
Maximum CPU time: 0 out of 60000
Maximum heap size: 0 out of 12000000
Number of callouts: 0 out of 0
Number of Email Invocations: 0 out of 10
Number of future calls: 0 out of 0
Number of queueable jobs added to the queue: 0 out of 1
Number of Mobile Apex push calls: 0 out of 10
08:33:30.350 (350869114)|CUMULATIVE_LIMIT_USAGE_END
08:33:30.0 (350916922)|CODE_UNIT_FINISHED|ProductInfoJobViaTalend
08:33:30.0 (352217971)|EXECUTION_FINISHED
And indeed, the record has not been updated. This is part of a batch job. In total I have 23 log files. The above segment is the last part of the last log file. The logfiles do not contain any errors or warnings. But also: all log files show zero activity in their summaries: no SOQL queries, no DML statements, no CPU time. While the details of the log files show all kinds of queries and updates.
The log file summaries even say "Number of callouts: 0 out of 0", while just above it I see lines like "CALLOUT_RESPONSE|[31]|System.HttpResponse[Status=OK, StatusCode=200]". The fact that I get so many log files tells me that 4 callouts were done. Salesforce is doing all kinds of things, but the summaries all say that nothing happened at all.
In my six years of Apex programming, I have not seen this behavior before. Who recognizes this? What am I doing wrong?