CODEWITHSUNDEEP
oracle-databasetoad
Zinab Taher
Zinab Taher

Reputation: 131

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

I'm using toad "Estimate Table Size ", it displays a lot of 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 the size and length?

Upvotes: 3

Views: 2598

Answers (2)

doktorg
doktorg

Reputation: 197

I couldn't find any specific documentation but I'd expect DDL size is the size of the table if all rows we're filled to the max size. To get a proper estimate you need to press the scan button and then Est Size (Scan) will be updated which gives you a better idea of the actual size of the table.

Upvotes: 0

ajmalmhd04
ajmalmhd04

Reputation: 2602

Some points from Toad Help:

Avg Row Len (Scan) calculates avg row len based on the data that is currently in the table (ie., you need to take a scan using the scan tool).

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

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

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

Upvotes: 1

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