Transaction handling in ERP LN/BAAN

Example 1:

Consider running the below 2 3GLs concurrently,

1.       otdsndtestdb

2.       otdsndtestdb2

Imagine db.update of both the 3GL is executed  and we kept  break point at the commit transaction statement of both.

Now we first execute the commit.transaction() statement of first 3GL.

And then when we execute the commit.transaction of 2^nd 3GL the cursor is taken to the db.retry.point() and then again the new values of record is read and is updated and then committed thereafter.

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 Example 2:

  

Doing db.update on the same record twice for the same record selected with “for update” clause is ok.

But once you commit the changes inside the select for update on a record you cannot do db.update() on the same record. See the below example, where the system will fail in the second db.update statement. That's because the “for update” delayed lock mechanism will release the delayed lock on the current record inside selectdo once we do commit. Thus the next db.update will  fail.

Again, having multiple commits inside a selectdo is fine. Below code will work:-