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What are the columns displayed in "Size of Calculation Table" in Toad? can anyone explain them?

I am using toad "Estimate Table Size", it displays many columns:

   AVG Row Len (states) 
   Est Size (states)
   Max Row Len (DDL)
   Est Size (DDL)
   AVG Row Len (scan) 
   Est Size (Scan)

Can anyone explain the columns? What is the difference between size and length?

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Some points of help about the toad:

Len Average (Scan) calculates the average len row based on the data that is currently in the table (i.e. you need to scan with a scan tool).



Avg Row Len (statistics) pulls the length of the avg row that is stored by Oracle the last time the table statistics were collected (based on the data in the table at the time the statistics were collected).

Max Row Len (DDL) pulls the maximum row length depending on the types and number of columns.

If none of these methods are applicable, you can enter your number in Avg Row Len (User). For example, if you have sample data, but you know that the sample data has values ​​in fields that are too small, then you can scan and then put a number slightly larger than Avg Row Len (Scan) into Avg Row Len (User ).

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I couldn't find any specific documentation, but I would expect the DDL size to be the size of the table if all rows are filled to the maximum size. To get the correct estimate you need to click the scan button and then the Est Size (Scan) parameter will be updated to give you an idea of ​​the actual table size.



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