Re: exp: why have statistics=estimate option?

Also,
You can't assume the row count has been computed previously. It would have had to have been analyzed previously (am i missing something?)

Steve

;tkyte_at_us.oracle.com (Thomas J. Kyte) wrote:
;>because stats collection is more then counting rows....
;>
;>it is counting discrete values within a column (lots of sort space needed for
;>near unique columns)
;>
;>it is finding high/low key values (ranges)
;>
;>in later versions it is creating histograms of data distribution
;>
;>and so on....
;>
;>
;>On Mon, 30 Dec 1996 18:45:32 GMT, chuckh_at_dvol.com (Chuck Hamilton) wrote:
;>
;>>Maybe this is a dumb question, but why even have the
;>>'statistics=estimate' option in the export utility? When a table gets
;>>imported, the _exact_ number of rows imported is already available.
;>>Why not just use that number to populate DBA_TABLES.NUM_ROWS instead
;>>of going through the time consuming process of issuing an ANALYZE
;>>TABLE command?
;>>--
;>>Chuck Hamilton
;>>chuckh_at_dvol.com
;>>
;>>This message delivered by electronic sled dogs. WOOF!
;>
;>Thomas Kyte
;>Oracle Government
;>tkyte_at_us.oracle.com
;>
;>http://govt.us.oracle.com
;>
;>---- Check out Oracle Governments web site! -----
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;>
;>
;>-------------------
;>statements and opinions are mine and do not necessarily
;>reflect the opinions of Oracle Corporation
;

Steve Tahmosh
State Street Bank Received on Mon Dec 30 1996 - 00:00:00 CST