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From Atul Saroha <atul.sar...@snapdeal.com>
Subject Re: How to migrate MYSQL to cassandra -special case in scoop+datastax
Date Sun, 07 Feb 2016 11:18:26 GMT
Hi Sachin.

We can index on collection (either key or value in a map) and can use it in
query. But my concern is to migrate the data in this form from a MYSQL
table. Using some multi-threaded script and java program is an option but
scoop approach would have been better.

Moreover, I am even concerned about this statement mentioned in below link:

Keep collections small to prevent delays during querying because *Cassandra
reads a collection in its entirety. The collection is not paged internally.*

https://docs.datastax.com/en/cql/3.0/cql/cql_using/use_collections_c.html



Thanks and Regards
---------------------------------------------------------------------------------------------------------------------
Atul Saroha
*Sr. Software Engineer*
*M*: +91 8447784271 *T*: +91 124-415-6069 *EXT*: 12369
Plot # 362, ASF Centre - Tower A, Udyog Vihar,
 Phase -4, Sector 18, Gurgaon, Haryana 122016, INDIA

On Sat, Feb 6, 2016 at 5:42 AM, Sachin Uplaonkar <up.sachi@gmail.com> wrote:

> Hello Atul,
>
> Please follow the document:
> http://docs.datastax.com/en/cql/3.3/cql/cql_using/useIndexColl.html
>
> I tried below code:
>
> */**CREATE TABLE demo.phone (*
> * details MAP<text, text>,*
> * initials text,*
> * time timeuuid,*
> * PRIMARY KEY (initials, time)*
> *);**/*
>
> *//insert into phone (initials, time, details) values ('su', now(),
> {'Sachi': '408-797-9600'});*
> *//insert into phone(initials, time, details) values ('su', now(), {'Sam':
> '555-121-2222'});*
> *//insert into phone (initials, time, details) values ('NG', now(),
> {'National Geographic': '404-509-2000'});*
> *//create index IF NOT EXISTS map_index on phone (details);*
>
> *select * from phone where details contains key 'Sam';*
>
>
> *[image: Inline image 1]*
>
>
>
> On Fri, Feb 5, 2016 at 9:47 AM, Sachin Uplaonkar <up.sachi@gmail.com>
> wrote:
>
>> Adding to the above:
>>
>> - Search on Collection types is not yet supported in CQL. [Hence, if we
>> create the table as per your model, we will not be able to query on it]
>>
>> Refer:* http://www.datastax.com/dev/blog/cql3_collections
>> <http://www.datastax.com/dev/blog/cql3_collections> *[Section: *Things
>> to Know*]
>>
>> On Fri, Feb 5, 2016 at 8:25 AM, Sachin Uplaonkar <up.sachi@gmail.com>
>> wrote:
>>
>>> Hello Atul,
>>>
>>> I am new to Cassandra but below is the thing which I tried:
>>>
>>> ** Not sure if this was intended by you **
>>>
>>> CREATE TABLE demo.phone (
>>> details MAP<text, text>,
>>> initials text,
>>> time timeuuid,
>>> PRIMARY KEY (initials, time)
>>> );
>>>
>>> insert into phone (initials, time, details) values ('su', now(),
>>> {'Sachi': '408-797-9600'});
>>> insert into phone(initials, time, details) values ('su', now(), {'Sam':
>>> '555-121-2222'});
>>>
>>>
>>> select * from phone;
>>>
>>>
>>> Results:
>>>
>>> [image: Inline image 1]
>>>
>>> On Thu, Feb 4, 2016 at 11:55 PM, Atul Saroha <atul.saroha@snapdeal.com>
>>> wrote:
>>>
>>>> MySQL Table:
>>>> User | PhoneNumber
>>>> --------------------------------
>>>> raman    1234
>>>> bhuvan  2345
>>>> atul       5678
>>>>
>>>> Using single Collection column and map collection :
>>>>
>>>> Phone Number
>>>> ---------------------------
>>>> Map <raman,1234>
>>>> <bhuvan,2345>
>>>> <atul,5678>
>>>>
>>>> Want to transform data in this way, i.e. key is mapped from value of
>>>> "user" column in the map.
>>>>
>>>> Any help will be appreciated.
>>>>
>>>>
>>>>
>>>>
>>>> ---------------------------------------------------------------------------------------------------------------------
>>>> Atul Saroha
>>>> *Sr. Software Engineer*
>>>> *M*: +91 8447784271 *T*: +91 124-415-6069 *EXT*: 12369
>>>> Plot # 362, ASF Centre - Tower A, Udyog Vihar,
>>>>  Phase -4, Sector 18, Gurgaon, Haryana 122016, INDIA
>>>>
>>>
>>>
>>>
>>> --
>>> Regards,
>>> Sachin S Uplaonkar.
>>>
>>
>>
>>
>> --
>> Regards,
>> Sachin S Uplaonkar.
>>
>
>
>
> --
> Regards,
> Sachin S Uplaonkar.
>

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