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Archives of the TeradataForum
Message Posted: Mon, 24 Oct 2005 @ 12:39:37 GMT
| Subj: | | Use of Insert/Select Versus Fastload |
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| From: | | Anomy Anom |
<-- Anonymously Posted: Monday, October 24, 2005 07:42 -->
Our installation allows large numbers of end users to do their own transformations into their own subject oriented data marts from host system
tables on Teradata. The typical process is to do multi table joins and produce either filtered unit records or summarised records into a table
using Create table ..Insert into.select a,b,c etc. Tables involved could have up to 85M rows with perhaps 50% of the rows being selected into the
created table. We have recently been advised that this is an inefficient and dangerous practice and that Teradata don't recommend the insert
select process for more than 10,000 rows. We were recommended to use Multiload or Fastload. As I understand it though both of these utilities
use a flat file and it doesn't seem efficient to me to export data from a Teradata table to a flat file and then Multiload them back into a
results table. Any advice would be appreciated.
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