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From <pco...@cegetel.net>
Subject Re: Re: Re: Cassandra DataModeling recommendations
Date Tue, 06 Dec 2011 08:31:54 GMT
Thanks to both of you for these very useful and interesting links/proposals.

Best Regards

========================================


 Hi 
 Thanks for the answer, as I read the book on Cassandra, I was not aware  at that time on
Composite Key which I recently discovered.
 
Composite Type's are useful for handling data-versions.   
 
 
 You mentioned a TTL and let the database remove the date for me. I  never read about that.
Is it possible without an external batch ?
  
Yes, TTL if set on column, auto delete column for you. 
 
  I will try to rephrase in any case my goal:
 
 Storage:
 - I would like to store for a user (identified by its id) several carts (BLOB).
 
  - Associated to these carts, I would like to attach metadata like expiration date and possibly
others.
 
 Queries/tasks:
 - I would like to be able to retrieve all the carts of a given userId.
  
I would use timeline with TTL for carts as separate CF. And cart_Id to reverse index in userId
CF with TTL set on columns.  


  - I would like to have a mean to remove expired carts.
 set TTL on each column. 

 
1.
cartCF{
 cart1_uuidkey:{
   metadata_column:ttl
 }
 cart2_uuidkey:{
   metadata_column:ttl
}
.
.
.cartN_uuidkey:{
  metadata_column:ttl
}
}

2.
userIdCF:{
 user1:{
    id:user1 //hack : to prevent unwanted behavior one column with no ttl.
     cart1:cart1_uuidkey:ttl
    cart2:........ttl
    cart3:........ttl
}
user2:{
    id:user2  
    cart1:cartX_uuidkey:ttl
     cart2:cart4........:ttl
    cart3:cartM........ttl

}

}

/Samal


 

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