reason loads are faster in an empty table

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Ted

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Oct 20, 2011, 10:47:23 AM10/20/11
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I had this question posed to me by a user and I wanted to get some
feedback from the group.

I am assuming that it is cause by reworking the indexes on the table
( eg more indexes more ordering)

Is this correct or is there other reasons. Could it be due to table
fragmentation ....


Thanks in advance

Mark Mumy

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Oct 20, 2011, 11:48:08 AM10/20/11
to iq...@googlegroups.com
Do the tables have HG indexes or just FPs?

An empty table will have empty HG indexes so that the load process won't
have to integrate the new data with any existing index structures.

All other index structures (except TEXT and WD) are heap structures and will
just load to the end (or beginning since it's empty) of the table.

Also, since the table is empty there is no searching for deleted rows
(Append_Load=OFF) so that will save time too.

Mark

============================================================


Thanks in advance

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