incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jimmy Lin <y2klyf+w...@gmail.com>
Subject data model question : finding out the n most recent changes items
Date Wed, 10 Jul 2013 06:51:28 GMT
I have an application that need to find out the n most recent modified
files for a given user id. I started out few tables but still couldn't get
what i want, I hope someone get point to some right direction...

See my tables below.

#1 won't work, because file_id's timeuuid contains creation time, not the
modification time.

#2 won't work, because i can't order by a non primary key
column(modified_date)

#3,#4 although i can now get  a time series of modification time of each
file belongs to a user, my return list may still not accurate because a
single directory could have lot of modification changes. I basically end up
pulling out series of modification timestamp for the same directory.

Any suggestion?

Thanks


#1

CREATE TABLE user_file (

user_id uuid,

file_id timeuuid,

PRIMARY KEY(user_id, file_id)

);


#2

CREATE TABLE user_file (

user_id uuid,

file_id timeuuid,

modified_date timestamp,

PRIMARY KEY(user_id, file_id)

);


#3

CREATE TABLE user_file (

user_id uuid,

file_id timeuuid,

modified_date timestamp,

PRIMARY KEY(user_id, file_id, modified_date)

);


#4

CREATE TABLE user_file (

user_id uuid,

modified_date timestamp,

file_id timeuuid,

PRIMARY KEY(user_id, modified_date, file_id)

);

Mime
View raw message