Jorge Godoy wrote on 12.08.2006 01:33:
I was trying to solve a problem on an old system and realized that there might
be some better approach for doing what I need.
We have some documents that need to be ordered sequentially and without gaps.
I could use a sequence, but if the transaction fails then when I rollback the
sequence will already have been incremented.
So, today I have a control table and I acquire a SHARE ROW EXCLUSIVE lock to
it, read the value, increase it, do what I need and then I COMMIT the
transaction, ensuring that the sequence has no gaps.
Is there a better way to guarantee that there will be no gaps in my sequence
if something goes wrong with my transaction?
What do you do if a document gets deleted? Renumber the "following" documents so
that no gaps are present in the already used ids?
Thomas
