ore a separate "name with no data"
> column.
>
> From: Patrick de Torcy [mailto:pdeto...@gmail.com]
> Sent: Wednesday, June 08, 2011 4:00 AM
> To: user@cassandra.apache.org
> Subject: Re: how to know there are some columns in a row
>
> There is no reason for ambig
| I am pretty sure this would cut down on network traffic, but not on Disk
IO or CPU use.
Well, that's the same for the get_count method !
I think that would be ok,since the network traffic is the real problem (big
values...). To store the column names in a separate column could be a
solution of
data" column.
From: Patrick de Torcy [mailto:pdeto...@gmail.com]
Sent: Wednesday, June 08, 2011 4:00 AM
To: user@cassandra.apache.org
Subject: Re: how to know there are some columns in a row
There is no reason for ambiguities...
We could add in the api anot
There is no reason for ambiguities...
We could add in the api another method call (similar to get_count) :
get_columnNames
-
list
get_columnNames(key, column_parent, predicate, consistency_level)
Get the columns names present in column_parent within the predicate.
The method is not O(
> If you have a method to retrieve the number of columns of a row (without
> their values), I can't see why you couldn't retrieve the column names
> (without their values). It's perharps harder than I think... But it would be
> rather useful !
Internally this just gets the full columns and co
There might not be a built-in way to do this, but if you make two rows for
each author, eg:
nabokov_fulltext [ 'lolita' : 'Lolita, light of my life ...' , ...]
nabokov_bookindex [ 'lolita' : None , ... ]
you could query the bookindex for each author without cassandra having to
load the full texts
But I want values in my columns... Imagine a cf with authors as keys. Each
author has written several books. So each row has columns with the title as
column names and the text of the book as value (ie a lot of data). If a user
wants to know the different books for an author, I'd like to be able to
You can create columns without values.
Are you talking about reading them back through the API ?
I would suggest looking at your data model to see if there is a better way to
support your read patterns.
Cheers
-
Aaron Morton
Freelance Cassandra Developer
@aaronmorton
http://
It would be definetely useful to be able to have columns (or super columns)
names WITHOUT their values. If these ones are pretty big or if there are a
lot of columns, that would generate traffic not necessarily needed (if in
the end you are just interrested by some column).
Moreover it doesn't seem
> Thanks you very much.
> but I'm afraid it's not a graceful means if there are billion columns in a
> row.
>
> 发件人： Michal Augustýn
> 收件人： user@cassandra.apache.org; Yonder
> 发送日期： 2011年6月2日, 星期四, 下午 9:25
> 主题: Re: how to know there are some columns in a
Thanks you very much.
but I'm afraid it's not a graceful means if there are billion columns in a row.
>
>发件人： Michal Augustýn
>收件人： user@cassandra.apache.org; Yonder
>发送日期： 2011年6月2日, 星期四, 下午 9:25
>主题: Re: how to know there are so
Hi,
just use "get" Thrift method where "super_column" and "column"
attributes in ColumnPath structure are empty. Yes, it returns both
column names and values but I'm afraid there is no Thrift-way how to
get column names only.
Augi
2011/6/2 Yonder :
> Dear all,
>
> Is there any methods to list co
Dear all,
Is there any methods to list column names in a row?
Thanks,
Yonder
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