On Wed, May 13, 2015 at 4:37 AM, Peer, Oded wrote:
> The cost of issuing an UPDATE that won’t update anything is compaction
> overhead. Since you stated it’s rare for rows to be updated then the
> overhead should be negligible.
>
It's also the cost of seeking into tables which contain the row f
t;]
Sent: Wednesday, May 13, 2015 3:13 PM
To: user@cassandra.apache.org<mailto:user@cassandra.apache.org>
Subject: Re: Updating only modified records (where lastModified < current date)
> I don’t understand the ETL use case and its relevance here. Can you provide
> more details?
be stored?
>>
>> On Wed, May 13, 2015 at 5:17 PM, Peer, Oded wrote:
>>
>>> It will cause an overhead (compaction and read) as I described in the
>>> previous email.
>>>
>>>
>>>
>>> *From:* Ali Akhtar [mailto:ali
gt;>
>> Now you have two values of V in the DB: ,
>>
>> When you read the value of V from the DB you read both , ,
>> Cassandra resolves the conflict by comparing the timestamp and returns V.
>>
>> Compaction will later take care and remove from the DB.
>>
&g
il.com<mailto:ali.rac...@gmail.com>]
Sent: Wednesday, May 13, 2015 3:13 PM
To: user@cassandra.apache.org<mailto:user@cassandra.apache.org>
Subject: Re: Updating only modified records (where lastModified < current date)
> I don’t understand the ETL use case and its relevance here. Can
ed in the
> previous email.
>
>
>
> *From:* Ali Akhtar [mailto:ali.rac...@gmail.com]
> *Sent:* Wednesday, May 13, 2015 3:13 PM
>
> *To:* user@cassandra.apache.org
> *Subject:* Re: Updating only modified records (where lastModified <
> current date)
>
>
&
It will cause an overhead (compaction and read) as I described in the previous
email.
From: Ali Akhtar [mailto:ali.rac...@gmail.com]
Sent: Wednesday, May 13, 2015 3:13 PM
To: user@cassandra.apache.org
Subject: Re: Updating only modified records (where lastModified < current date)
> I
ows to be updated then the
> overhead should be negligible.
>
>
>
> The easiest way to convert a milliseconds timestamp long value to
> microseconds is to multiply by 1000.
>
>
>
> *From:* Ali Akhtar [mailto:ali.rac...@gmail.com]
> *Sent:* Wednesday, May 13, 2015 2:15 PM
>
in Cassandra updates specific rows. All of them are updated, nothing is
ignored.
From: Ali Akhtar [mailto:ali.rac...@gmail.com]
Sent: Wednesday, May 13, 2015 2:43 PM
To: user@cassandra.apache.org
Subject: Re: Updating only modified records (where lastModified < current date)
Its rare for an ex
:* Wednesday, May 13, 2015 2:15 PM
> *To:* user@cassandra.apache.org
> *Subject:* Re: Updating only modified records (where lastModified <
> current date)
>
>
>
> Would TimeUnit.MILLISECONDS.toMicros( myDate.getTime() ) work for
> producing the microsecond timestamp ?
>
>
[mailto:ali.rac...@gmail.com]
Sent: Wednesday, May 13, 2015 2:15 PM
To: user@cassandra.apache.org
Subject: Re: Updating only modified records (where lastModified < current date)
Would TimeUnit.MILLISECONDS.toMicros( myDate.getTime() ) work for producing
the microsecond timestamp ?
On Wed, May
ed you have in the DB.
>>>
>>>
>>>
>>> Updates to values don’t create tombstones. Only deletes (either by
>>> executing delete, inserting a null value or by setting a TTL) create
>>> tombstones.
>>>
>>>
>>>
>>>
>>
>>
>>
>> *From:* Ali Akhtar [mailto:ali.rac...@gmail.com]
>> *Sent:* Wednesday, May 13, 2015 1:27 PM
>> *To:* user@cassandra.apache.org
>> *Subject:* Updating only modified records (where lastModified < current
>> date)
>>
>>
>>
>>
; executing delete, inserting a null value or by setting a TTL) create
> tombstones.
>
>
>
>
>
> *From:* Ali Akhtar [mailto:ali.rac...@gmail.com]
> *Sent:* Wednesday, May 13, 2015 1:27 PM
> *To:* user@cassandra.apache.org
> *Subject:* Updating only modified records (whe
> lastModified you have in the DB.
>>>
>>>
>>>
>>> Updates to values don’t create tombstones. Only deletes (either by
>>> executing delete, inserting a null value or by setting a TTL) create
>>> tombstones.
>>>
>&
t;
>>
>>
>>
>> *From:* Ali Akhtar [mailto:ali.rac...@gmail.com]
>> *Sent:* Wednesday, May 13, 2015 1:27 PM
>> *To:* user@cassandra.apache.org
>> *Subject:* Updating only modified records (where lastModified < current
>> date)
>>
>>
>>
&g
gt;
> Updates to values don’t create tombstones. Only deletes (either by
> executing delete, inserting a null value or by setting a TTL) create
> tombstones.
>
>
>
>
>
> *From:* Ali Akhtar [mailto:ali.rac...@gmail.com]
> *Sent:* Wednesday, May 13, 2015 1:27 PM
> *T
or by setting a TTL) create tombstones.
From: Ali Akhtar [mailto:ali.rac...@gmail.com]
Sent: Wednesday, May 13, 2015 1:27 PM
To: user@cassandra.apache.org
Subject: Updating only modified records (where lastModified < current date)
I'm running some ETL jobs, where the pattern is the fo
I'm running some ETL jobs, where the pattern is the following:
1- Get some records from an external API,
2- For each record, see if its lastModified date > the lastModified i have
in db (or if I don't have that record in db)
3- If lastModified < dbLastModified, the item wasn't changed, ignore it
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