Morning all,
When doing an import with constraints=n, has anyone ever had the import create
multiple duplicate records?
I did a test import using a single table that has 27 million rows. In
production, there is a column used as a PK which thus has a unique constraint.
First pass through I did an import with the indexes=n, constraints=n. import
completes successfully, rows are in.
Then, I started the import again with rows=n, indexes=y, constraints=y. Import
failed, inability to create unique index on the column indicated due to
duplicate key values.
Huh. Tried to manually create the index. Same failure. Huh again.
I built a quick non-unique index on the column. Couple of sql queries later
and I determine that there are 20,189 duplicate values. I run the same
queries on my production system (where I got the export) and no duplicates are
there.
I did the export of the data while the system was up live and users active on
it.
Based on this, it almost seems like either my import corrupted somehow, or my
export. How do I determine if my file is bad, or my import is bad? My only
thought is to try and run it again or to possible see if the unique data is at
the end of the table (reflecting the activity going on in the production system
at the time of the export.).
