So no one is able to help?
From: Anthony Ikeda [mailto:anthony.ik...@cardlink.com.au] Sent: Monday, 28 June 2010 12:36 PM To: user@cassandra.apache.org Subject: Understanding SuperColumns I seem to be scratching my head about how to model Super Columns properly and how they relate to a 1 to many kind of relationship. For example: UserAccounts = { "PB12345": { firstname: "Paul", surname: "Brown", address: {street: "Main St", suburb: "Springfield", state: "NY"} } } Here I'm using address as a super column based on some of the examples I've come across. What if Paul has multiple addresses or if an address belonged to more than one person? Is the following still valid? UserAccounts = { "PB12345" : { firstname: "Paul", surname: "Brown" }, "SB12345": { firstname: "Sue", surname: "Brown" } } Addresses = { "address1": { street: "Main St", suburb: "Springfield", state: "NY", owners: { "PB12345": {createdDate: "20100626"}, "SB12345": {createdDate: "20100522"} } }, "address2": { street: "Berry St", suburb: "New York", state: "NY", owners: { "PB12345": {moveInDate: "20100421"} } }, "address3": { street: "5th Avenue", suburb: "Springfield", state: "NY" } } AddressesByType = { "home": { address1: { street: "Main St", suburb: "Springfield", state: "NY", owner="PB12345"} }, "work": { address2: {street: "Berry St", suburb: "New York", state: "NY", owner="PB12345"}, address3: {street: "5th Avenue", suburb: "Springfield", state: "NY"} } } AddressByCity = { "New York": { "address2": {createdDate: "01/01/1937"} }, "Springfield": { "address1": {createdDate: "12/05/1940"}, "address3": {createdDate: "12/12/1880"} } } I understand that: 1. There is a lack of relationships in modelling with NoSQL systems between entities 2. Data is represented in a way that you need to query it (e.g. I need a model that represents all addresses by type, all addresses by city, etc) But to what degree do I end up tearing the data apart? Say my query is: Get all Work addresses in New York and the address owner. Steps to get the data would be: 1. Find out which addresses are classified as "Type=Work" and get the primary key of the super column (returns [AddressByType][work][address2] and [AddressByType][work] [address3]) 2. Then get all the addresses located in "New York" (returns [AddressByCity][New York][address2]) 3. Then get "owner" field from my records returned in Step 1 ([AddressByType][work][address2][owner="PB12345"], address3 is abandoned) 4. Then retrieve the User details and Address details using "address2" and "PB12345" using a kind of union...I think. Am I over complicating this? Anthony Ikeda Java Analyst/Programmer Cardlink Services Limited Level 4, 3 Rider Boulevard Rhodes NSW 2138 Web: www.cardlink.com.au | Tel: + 61 2 9646 9221 | Fax: + 61 2 9646 9283 ********************************************************************** This e-mail message and any attachments are intended only for the use of the addressee(s) named above and may contain information that is privileged and confidential. If you are not the intended recipient, any display, dissemination, distribution, or copying is strictly prohibited. If you believe you have received this e-mail message in error, please immediately notify the sender by replying to this e-mail message or by telephone to (02) 9646 9222. Please delete the email and any attachments and do not retain the email or any attachments in any form. ********************************************************************** _____________________________________________________________________ This e-mail has been scanned for viruses by MCI's Internet Managed Scanning Services - powered by MessageLabs. For further information visit http://www.mci.com ********************************************************************** This e-mail message and any attachments are intended only for the use of the addressee(s) named above and may contain information that is privileged and confidential. If you are not the intended recipient, any display, dissemination, distribution, or copying is strictly prohibited. If you believe you have received this e-mail message in error, please immediately notify the sender by replying to this e-mail message or by telephone to (02) 9646 9222. Please delete the email and any attachments and do not retain the email or any attachments in any form. **********************************************************************
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