RE: avg_row_len

From: Powell, Mark <mark.powell2_at_hp.com>
Date: Fri, 9 Mar 2012 17:48:16 +0000
Message-ID: <7C4BF3B32B80CC44AE37D31B172415937DD8F7C22F_at_GVW1337EXC.americas.hpqcorp.net>



There is also overhead that will be required to hold the new rows so avg_row_len X num_rows X overhead_factor will provide a better estimate. I suggest estimating the new table size for the full load and then look to see how full the current table is. Some of your data may fit into the existing space. Finally you have to take a look at your net space need in relation to the table extent allocation method in use.

-----Original Message-----
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Timo Raitalaakso Sent: Thursday, March 08, 2012 4:08 PM
To: oracle-l_at_freelists.org
Subject: Re: avg_row_len

The estimate would be something like your formula. Check also LAST_ANALYZED and does NUM_ROWS match count(*).

http://docs.oracle.com/cd/E11882_01/server.112/e25513/statviews_2117.htm#i1592091

|AVG_ROW_LEN*| |NUMBER| Average length of a row in the table (in bytes)

How full are the used column data types populated? Does_ALL_TAB_COLUMNS AVG_COL_LEN match DATA_LENGTH _http://docs.oracle.com/cd/E11882_01/server.112/e25513/statviews_2103.htm#I1020277 Will the future 600k row be poplated with similar data? You will not know. But it is an estimate.

--
Timo Raitalaakso
http://rafudb.blogspot.com

8.3.2012 22:43, Zelli, Brian kirjoitti:

> So I can see that the average row length in my table is 263. Is that bytes? And if I want to estimate another 600,000 rows I multiply the 600,000 by 263?
>
> ciao,
> Brian
>
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Received on Fri Mar 09 2012 - 11:48:16 CST

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