Huge table spike but no change in records coming avg

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Enthusiast

Huge table spike but no change in records coming avg

Hi All,

we have TD 16.20.One table was till 08/05 100GB on 08/06 it bcom 800GB.There was no diffrenece except 4 new columns were added.(char(5),cahr(5),char(6),char(1)).Load was not spiked as almost same number of rows got incresed.Nowif i tried to load a empty table from this 800GB table exclusing these 4 new columns still its coming as 800GB.Can anybody give me any clue.I also compress NUlls but of no use.Help me to solve 

 

5 REPLIES
Senior Apprentice

Re: Huge table spike but no change in records coming avg

Hi,


So essentially why does a table in Teradata get bigger?

 

  1. The row is longer. You've added 17 characters, nominally between 17 and 34 bytes depending on Latin/Unicode character set. What was the row length before these columns were added?
  2. There are more rows. You say that "Load was not spiked as almost same number of rows got incresed". Does this mean this is a work table which gets emptied and then loaded with a new batch of data, or the number of rows just increases each day?
  3. Compression has been changed/removed. How about BLC? Is that still in place or has it been removed for this table? even with BLC still in place it is possible that the effect of BLC changes, but I wouldn't expect it to make this much difference.
  4. Additional indexes. Again unlikely to make this much difference.

HTH

Dave

Ward Analytics Ltd - information in motion
www: http://www.ward-analytics.com
Enthusiast

Re: Huge table spike but no change in records coming avg

Hi,

The table had 916 columns on 08/05 and 920 on 08/06..No MVC on table..but they use BLC to load the data from old to new table.This is not a stage table so no truncate and load,almost same number of rows ger added everyday.No index change.The table has only UPI and PPI.I tried with removing these 4 columns and load same table to empty table but still 800GB,i tried to compress nulls but still 800GB :(

Enthusiast

Re: Huge table spike but no change in records coming avg

Also,when i deleted all data from 08/06 ..as the table was 100GB till 08/05..it didn't decresed the table size.It was still 800GB

Enthusiast

Re: Huge table spike but no change in records coming avg

Hi,

 

The source table had BLC enabled ..i enables BLC for session and it went back to 100GB..Thank u :)

Senior Apprentice

Re: Huge table spike but no change in records coming avg

I'm glad you got that sorted. Thanks for sharing the solution.

Cheers,

Dave

Ward Analytics Ltd - information in motion
www: http://www.ward-analytics.com