On Sep 14, 2006, at 9:16 PM, Golden Liu wrote:
Suppose there are too tuples in a table t, named
id
---
1
2
and there is a unique index on id. Now we do an update on table t
update t set id=id+1
Since PG executes the update one tuple at a time, it updates tuple "1"
to "2" and insert it into the index. Before insert into the index, it
check whether the id is still "unique" or not. No, it's not, old tuple
"2" is still in the table. So an error is raised.
I try to solve this problem this way:
First, update the table t but DON'T update the index.
Next, find all the tuples updated by this command and insert them into
the unique index.
Isn't that what a deferred constraint normally does?
I suspect that your change adds a non-trivial overhead, which means
we don't want it to be the normal case.
--
Jim Nasby [EMAIL PROTECTED]
EnterpriseDB http://enterprisedb.com 512.569.9461 (cell)
--
Jim Nasby [EMAIL PROTECTED]
EnterpriseDB http://enterprisedb.com 512.569.9461 (cell)
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