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Date: Thu, 16 Jun 2011 00:30:56 +0530 (IST)
From: chovatia jaydeep <chovatia_jaydeep@yahoo.co.in>
Reply-To: chovatia jaydeep <chovatia_jaydeep@yahoo.co.in>
Subject: Re: When does it make sense to use TimeUUID?
To: "user@cassandra.apache.org" <user@cassandra.apache.org>
In-Reply-To: <BANLkTi=ai5bdW9imMNx0Ab6esLogP9LBnA@mail.gmail.com>
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Hi Sameer,=0A=0AOne example is, store all the tweets for a given user in a =
Column =0AFamily, where row key is user name/user id and column name is of =
=0ATimeUUID type that=A0 represents tweet arrival time. User would generall=
y =0Alike to see the tweets sorted based on its arrival time. So TimeUUID =
=0Awill help here.=0A=0AThank you,=0AJaydeep=0A=0A=0A______________________=
__________=0AFrom: Sameer Farooqui <cassandralabs@gmail.com>=0ATo: user@cas=
sandra.apache.org=0ASent: Tuesday, 14 June 2011 5:16 PM=0ASubject: When doe=
s it make sense to use TimeUUID?=0A=0A=0AI would like to store some timesta=
mped user info in a Column Family with the usernames as the row key and dif=
ferent timestamps as column names. Each user might have a thousand timestam=
ped data.=0A=0AI understand that the ver 1 UUIDs that Cassandra combines th=
e MAC address of the computer generating the UUID with the number of 100-na=
nosecond intervals since the beginning of the Gregorian calendar.=0A=0ASo, =
if user1 had data stored for an event at Jan 30, 2011/2:15pm and user2 had =
an event at the exact same time, the data could potentially be stored in di=
fferent column names? So, I would have to know the MAC of the generating co=
mputer in order to do a column slice, right?=A0=0A=0AWhen does it make sens=
e to use TimeUUID vs just a time string like 20110130141500 and comparator =
type UTF8?=0A=0A- Sameer
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<html><body><div style=3D"color:#000; background-color:#fff; font-family:ar=
ial, helvetica, sans-serif;font-size:12pt"><div><span>Hi Sameer,</span></di=
v><div><span><br></span></div><div><span>One example is, store all the twee=
ts for a given user in a Column =0AFamily, where row key is user name/user =
id and column name is of =0ATimeUUID type that&nbsp; represents tweet arriv=
al time. User would generally =0Alike to see the tweets sorted based on its=
 arrival time. So TimeUUID =0Awill help here.<br></span></div><div><br></di=
v>Thank you,<br>Jaydeep<div><br></div><div style=3D"font-family: arial, hel=
vetica, sans-serif; font-size: 12pt;"><div style=3D"font-family: times new =
roman, new york, times, serif; font-size: 12pt;"><font face=3D"Arial" size=
=3D"2"><hr size=3D"1"><b><span style=3D"font-weight:bold;">From:</span></b>=
 Sameer Farooqui &lt;cassandralabs@gmail.com&gt;<br><b><span style=3D"font-=
weight: bold;">To:</span></b> user@cassandra.apache.org<br><b><span style=
=3D"font-weight: bold;">Sent:</span></b> Tuesday, 14 June 2011 5:16 PM<br><=
b><span style=3D"font-weight: bold;">Subject:</span></b> When does it make =
sense to use TimeUUID?<br></font><br><div id=3D"yiv1327234343">I would like=
 to store some timestamped user info in a Column Family with the usernames =
as the row key and different timestamps as column names. Each user might ha=
ve a thousand timestamped data.<div><br></div><div>I understand that the ve=
r 1 UUIDs that Cassandra combines the MAC
 address of the computer generating the UUID with the number of 100-nanosec=
ond intervals since the beginning of the Gregorian calendar.</div>=0A<div><=
br></div><div>So, if user1 had data stored for an event at Jan 30, 2011/2:1=
5pm and user2 had an event at the exact same time, the data could potential=
ly be stored in different column names? So, I would have to know the MAC of=
 the generating computer in order to do a column slice, right?&nbsp;</div>=
=0A<div><br></div><div>When does it make sense to use TimeUUID vs just a ti=
me string like 20110130141500 and comparator type UTF8?</div><div><br></div=
><div>- Sameer</div>=0A</div><br><br></div></div></div></body></html>
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