RE: overhead of empty tables

[Jacques-Henri Berthemet]

The main overhead is that each table locks 1MB of Java heap, so if you have 
1000 tables it will use 1GB of RAM just for managing the tables, even if they 
are empty.

--
Jacques-Henri Berthemet

From: Alaa Zubaidi (PDF) [mailto:alaa.zuba...@pdf.com]
Sent: Friday, February 16, 2018 1:05 AM
To: user@cassandra.apache.org; Dinesh Joshi <dinesh.jo...@yahoo.com>
Subject: Re: overhead of empty tables

Thanks Dinesh,
We have 36332 files under the data folder

On Thu, Feb 15, 2018 at 3:45 PM, Dinesh Joshi 
<dinesh.jo...@yahoo.com.invalid<mailto:dinesh.jo...@yahoo.com.invalid>> wrote:
Each table in a keyspace is stored as a separate directory in the data 
directory. If you many tables you'll have a lot of files. Some file systems 
have issues dealing with a lot of files in a single directory. Other than that, 
there will likely be some book keeping overhead within the Cassandra process. 
How many tables are we talking about here?

Here's more information about it: 
https://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlHowDataWritten.html<https://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlHowDataWritten.html>

Dinesh


On Thursday, February 15, 2018, 3:34:49 PM PST, Alaa Zubaidi (PDF) 
<alaa.zuba...@pdf.com<mailto:alaa.zuba...@pdf.com>> wrote:


Is there any overhead if my keyspace contains many empty tables?
Thanks
Alaa

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Re: overhead of empty tables

[Alaa Zubaidi (PDF)]

Thanks Dinesh,
We have 36332 files under the data folder

On Thu, Feb 15, 2018 at 3:45 PM, Dinesh Joshi <
dinesh.jo...@yahoo.com.invalid> wrote:

> Each table in a keyspace is stored as a separate directory in the data
> directory. If you many tables you'll have a lot of files. Some file systems
> have issues dealing with a lot of files in a single directory. Other than
> that, there will likely be some book keeping overhead within the Cassandra
> process. How many tables are we talking about here?
>
> Here's more information about it: https://docs.datastax.com/
> en/cassandra/3.0/cassandra/dml/dmlHowDataWritten.html
>
> Dinesh
>
>
> On Thursday, February 15, 2018, 3:34:49 PM PST, Alaa Zubaidi (PDF) <
> alaa.zuba...@pdf.com> wrote:
>
>
> Is there any overhead if my keyspace contains many empty tables?
> Thanks
> Alaa
>
> *This message may contain confidential and privileged information. If it
> has been sent to you in error, please reply to advise the sender of the
> error and then immediately permanently delete it and all attachments to it
> from your systems. If you are not the intended recipient, do not read,
> copy, disclose or otherwise use this message or any attachments to it. The
> sender disclaims any liability for such unauthorized use. PLEASE NOTE that
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> be scanned by us and/or by external service providers to detect and prevent
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> and/or eliminate unsolicited promotional e-mails (“spam”). If you have any
> concerns about this process, please contact us at *
> *legal.departm...@pdf.com* *.*
>



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Alaa Zubaidi
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San Jose, CA 95110  USA
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fax: 408-938-6479
email: alaa.zuba...@pdf.com

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Re: overhead of empty tables

[Dinesh Joshi]

Each table in a keyspace is stored as a separate directory in the data 
directory. If you many tables you'll have a lot of files. Some file systems 
have issues dealing with a lot of files in a single directory. Other than that, 
there will likely be some book keeping overhead within the Cassandra process. 
How many tables are we talking about here?

Here's more information about it: 
https://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlHowDataWritten.html
Dinesh 

On Thursday, February 15, 2018, 3:34:49 PM PST, Alaa Zubaidi (PDF) 
 wrote:  
 
 Is there any overhead if my keyspace contains many empty tables?ThanksAlaa
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overhead of empty tables

[Alaa Zubaidi (PDF)]

Is there any overhead if my keyspace contains many empty tables?
Thanks
Alaa

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