|Subject||can't reproduce results transactions|
Is there a way I can draw a diagram and match it to my input in isql?
I am trying to set the default transaction in each of my isql clients that are open in separate windows.
In each isql I type: set transaction wait isolation level read committed.
I tried to make a chart like this to document what I am doing.
980- tid | 982
update | update/wait
commit (no error)
new tid - 984 | 982
update/wait | update
| commit (error)
984 | 986 new tid
on p. 196 of volume 2 it says:
with no record_version - "it blocks this transaction from writing a new version of the row...."
with wait : (allowable if - its own tid is newer than the other transactions tid)
I don't want to retype the exact wording out of helen's book because of copyright.
my diagram and the data in it don't make sense to me. on wait, if my tid is newer (higher #)
than the other tid, why do I get the deadlock error?
I hope there is an easy way for someone to demonstrate this to me.
I wish I had tried this experiment with trying to figure out transactions a long
time ago. I didn't realize I'd get this stuck.
I am really lost on this one. Not sure what I am missing.