I think that table example misses the point of chetan's functional requirement. he actually needs dynamic columns.
On Tue, Jan 20, 2015 at 8:12 PM, Xu Zhongxing <xu_zhong_x...@163.com> wrote: > Maybe this is the closest thing to "dynamic columns" in CQL 3. > > create table reivew ( > product_id bigint, > created_at timestamp, > data_key text, > data_tvalue text, > data_ivalue int, > primary key ((priduct_id, created_at), data_key) > ); > > data_tvalue and data_ivalue is optional. > > At 2015-01-21 04:44:07, "chetan verma" <chetanverm...@gmail.com> wrote: > > Hi, > > Adding to previous mail. For example: We have a column family named review > (with some arbitrary data in map). > > CREATE TABLE review( > product_id bigint, > created_at timestamp, > data_int map<text, int>, > data_text map<text, text>, > PRIMARY KEY (product_id, created_at) > ); > > Assume that these 2 maps I use to store arbitrary data (i.e. data_int and > data_text for int and text values) > when we see output on cassandra-cli, it looks like in a partition as : > <clustering_key>:data_int:map_key as column name and value as map value. > suppose I need to get this value, I couldn't do that with CQL3 but in > thrift its possible. Any Solution? > > On Wed, Jan 21, 2015 at 1:06 AM, chetan verma <chetanverm...@gmail.com> > wrote: > >> Hi, >> >> Most of the time I will be querying on product_id and created_at, but >> for analytic I need to query almost on all column. >> Multiple collections ideas is good but the only is cassandra reads a >> collection entirely, what if I need a slice of it, I mean >> columns for certain keys which is possible with thrift. Please suggest. >> >> On Wed, Jan 21, 2015 at 12:36 AM, Jonathan Lacefield < >> jlacefi...@datastax.com> wrote: >> >>> Hello, >>> >>> There are probably lots of options to this challenge. The more details >>> around your use case that you can provide, the easier it will be for this >>> group to offer advice. >>> >>> A few follow-up questions: >>> - How will you query this data? >>> - Do your queries require filtering on specific columns other than >>> product_id and created_at, i.e. the dynamic columns? >>> >>> Depending on the answers to these questions, you have several options, >>> of which here are a few: >>> >>> - Cassandra efficiently stores sparse data, so you could create >>> columns and not populate them, without much of a penalty >>> - Could use a clustering column to store a columns type and another >>> col (potentially clustering) to store the value >>> - i.e. CREATE TABLE foo (col1 int, attname text, attvalue text, >>> col4...n, PRIMARY KEY (col1, attname, attvalue)); >>> - where attname stores the name of the attribute/column and >>> attvalue stores the value of that attribute >>> - have seen users use this model and create a "main" attribute >>> row within a partition that stores the values associated with col4...n >>> - Could store multiple collections >>> - Others probably have ideas as well >>> >>> You may want to look in the archives for a similar discussion topic. >>> Believe this item was asked a few months ago as well. >>> >>> [image: datastax_logo.png] >>> >>> Jonathan Lacefield >>> >>> Solution Architect | (404) 822 3487 | jlacefi...@datastax.com >>> >>> [image: linkedin.png] <http://www.linkedin.com/in/jlacefield/> [image: >>> facebook.png] <https://www.facebook.com/datastax> [image: twitter.png] >>> <https://twitter.com/datastax> [image: g+.png] >>> <https://plus.google.com/+Datastax/about> >>> <http://feeds.feedburner.com/datastax> <https://github.com/datastax/> >>> >>> On Tue, Jan 20, 2015 at 1:40 PM, chetan verma <chetanverm...@gmail.com> >>> wrote: >>> >>>> Hi, >>>> >>>> I am creating a review system. for instance lets assume following are >>>> the attibutes of system: >>>> >>>> Review{ >>>> id bigint, >>>> product_id bigint, >>>> created_at timestamp, >>>> summary text, >>>> description text, >>>> pros set<text>, >>>> cons set<text>, >>>> feature_rating map<text, int> >>>> etc.... >>>> } >>>> I created partition key as product_id (so that all the reviews for a >>>> given product will reside on same node) >>>> and clustering key as created_at and id (Desc) so that reviews will be >>>> sorted by time. >>>> >>>> I can have more column and that requirement I want to fulfil by dynamic >>>> columns but there are limitations to it explained above. >>>> Could you please let me know the best way. >>>> >>>> On Tue, Jan 20, 2015 at 11:59 PM, Jonathan Lacefield < >>>> jlacefi...@datastax.com> wrote: >>>> >>>>> Hello, >>>>> >>>>> Have you looked at solving this challenge with clustering columns? >>>>> Also, please describe the problem set details for more specific advice >>>>> from >>>>> this group. >>>>> >>>>> Starting new projects on Thrift isn't the recommended approach. >>>>> >>>>> Jonathan >>>>> >>>>> [image: datastax_logo.png] >>>>> >>>>> Jonathan Lacefield >>>>> >>>>> Solution Architect | (404) 822 3487 | jlacefi...@datastax.com >>>>> >>>>> [image: linkedin.png] <http://www.linkedin.com/in/jlacefield/> [image: >>>>> facebook.png] <https://www.facebook.com/datastax> [image: twitter.png] >>>>> <https://twitter.com/datastax> [image: g+.png] >>>>> <https://plus.google.com/+Datastax/about> >>>>> <http://feeds.feedburner.com/datastax> <https://github.com/datastax/> >>>>> >>>>> On Tue, Jan 20, 2015 at 1:24 PM, chetan verma <chetanverm...@gmail.com >>>>> > wrote: >>>>> >>>>>> Hi, >>>>>> >>>>>> I am starting a new project with cassandra as database. >>>>>> I have unstructured data so I need dynamic columns, >>>>>> though in CQL3 we can achive this via Collections but there are some >>>>>> downsides to it. >>>>>> 1. Collections are used to store small amount of data. >>>>>> 2. The maximum size of an item in a collection is 64K. >>>>>> 3. Cassandra reads a collection in its entirety. >>>>>> 4. Restrictions on number of items in collections is 64,000 >>>>>> >>>>>> And no support to get single column by map key, which is possible via >>>>>> cassandra cli. >>>>>> Please suggest whether I should use CQL3 or Thrift and which driver >>>>>> is best. >>>>>> >>>>>> -- >>>>>> *Regards,* >>>>>> *Chetan Verma* >>>>>> *+91 99860 86634 <%2B91%2099860%2086634>* >>>>>> >>>>> >>>>> >>>> >>>> >>>> -- >>>> *Regards,* >>>> *Chetan Verma* >>>> *+91 99860 86634 <%2B91%2099860%2086634>* >>>> >>> >>> >> >> >> -- >> *Regards,* >> *Chetan Verma* >> *+91 99860 86634 <%2B91%2099860%2086634>* >> > > > > -- > *Regards,* > *Chetan Verma* > *+91 99860 86634 <%2B91%2099860%2086634>* > >
