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Archives of the TeradataForum
Message Posted: Thu, 10 Jul 2008 @ 14:47:21 GMT
| Subj: | | Re: How to Analyze tables in Teradata? |
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| From: | | Tewksbury, Kevin |
Let's follow up on this one just a little bit, as we came across this only a few weeks ago.
Yes, you are correct that the collect stats puts an access lock on the table and you cannot alter the table while the stats are being
collected. However, it does not prevent the deleting of the rows from the table. We had this scenario happen where one of our UNICA users was
running a flowchart, cancelled it and re-ran again. The problem was that they cancelled during a collect stats statement and the system was so
busy that it took a little while to actually cancel on Teradata. During this "split" second, they started the flowchart again and the first thing
that it does is delete the rows from the table. This caused a restart of the system. What we found in /etc/.osm is "5007: No more rows exist in
the requested range", which basically means that the collect stats was trying to read the next row couldn't find it nor did it get an EOF for the
table, so system had a restart.
We are on PTDBMS 6.1.1.51 and there is a DR fix for this scenario (not sure of the DR) but it is fixed in 6.1.1.56 and higher. Another work
around is to force a "read lock" on the table prior to collecting stats, and at this time, since we are going to be migrating to R12, we have
asked the UNICA admins to add a read lock statement to the collect stats statements that are generated by UNICA.
Just thought you all would like to know.
Kevin R Tewksbury
Sr. Database Administrator
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