You know what don't "go low" and suggest the recent un-subscriber on me.
If your so eager to deal with my pull request please review this one: I would rather you review this pull request: https://issues.apache.org/jira/browse/CASSANDRA-10825 On Mon, Oct 3, 2016 at 1:04 PM, Benedict Elliott Smith <bened...@apache.org> wrote: > Nobody is disputing that the docs can and should be improved to avoid this > misreading. I've invited Ed to file a JIRA and/or pull request twice now. > > You are of course just as welcome to do this. Perhaps you will actually > do it, so we can all move on with our lives! > > > > > On 3 October 2016 at 17:45, Peter Lin <wool...@gmail.com> wrote: > >> I've met clients that read the cassandra docs and then said in a big >> meeting "it's just like relational database, it has tables just like >> sqlserver/oracle." >> >> I'm not putting words in other people's mouth either, but I've heard that >> said enough times to want to puke. Does the docs claim cassandra is >> relational ? it absolutely doesn't make that claim, but the docs play >> loosey goosey with terminology. End result is it confuses new users that >> aren't experts, or technology managers that try to make a case for >> cassandra. >> >> we can make all the excuses we want, but that doesn't change the fact the >> docs aren't user friendly. writing great documentation is tough and most >> developers hate it. It's cuz we suck at it. There I said it, "we SUCK as >> writing user friendly documentation". As many people have pointed out, it's >> not unique to Cassandra. 80% of the tech docs out there suck, starting with >> IBM at the top. >> >> Saying the docs suck isn't an indictment of anyone, it's just the reality >> of writing good documentation. >> >> On Mon, Oct 3, 2016 at 12:33 PM, Jonathan Haddad <j...@jonhaddad.com> >> wrote: >> >>> Nobody is claiming Cassandra is a relational I'm not sure why that keeps >>> coming up. >>> On Mon, Oct 3, 2016 at 10:53 AM Edward Capriolo <edlinuxg...@gmail.com> >>> wrote: >>> >>>> My original point can be summed up as: >>>> >>>> Do not define cassandra in terms SMILES & METAPHORS. Such words include >>>> "like" and "close relative". >>>> >>>> For the specifics: >>>> >>>> >>>> Any relational db could (and I'm sure one does!) allow for sparse >>>> fields as well. MySQL can be backed by rocksdb now, does that make it not a >>>> row store? >>>> >>>> >>>> Lets draw some lines, a relational database is clearly defined. >>>> >>>> https://en.wikipedia.org/wiki/Edgar_F._Codd >>>> >>>> Codd's theorem <https://en.wikipedia.org/wiki/Codd%27s_theorem>, a >>>> result proven in his seminal work on the relational model, equates the >>>> expressive power of relational algebra >>>> <https://en.wikipedia.org/wiki/Relational_algebra> and relational >>>> calculus <https://en.wikipedia.org/wiki/Relational_calculus> (both of >>>> which, lacking recursion, are strictly less powerful thanfirst-order >>>> logic <https://en.wikipedia.org/wiki/First-order_logic>).[*citation >>>> needed <https://en.wikipedia.org/wiki/Wikipedia:Citation_needed>*] >>>> >>>> As the relational model started to become fashionable in the early >>>> 1980s, Codd fought a sometimes bitter campaign to prevent the term being >>>> misused by database vendors who had merely added a relational veneer to >>>> older technology. As part of this campaign, he published his 12 rules >>>> <https://en.wikipedia.org/wiki/Codd%27s_12_rules> to define what >>>> constituted a relational database. This made his position in IBM >>>> increasingly difficult, so he left to form his own consulting company with >>>> Chris Date and others. >>>> >>>> Cassandra is not a relational database. >>>> >>>> I am have attempted to illustrate that a "row store" is defined as >>>> well. I do not believe Cassandra is a "row store". >>>> >>>> >>>> >>>> "Just because it uses log structured storage, sparse fields, and >>>> semi-flexible collections doesn't disqualify it from calling it a "row >>>> store"" >>>> >>>> What is the definition of "row store". Is it a logical construct or a >>>> physical one? >>>> >>>> Why isn't mongo DB a "row store"? I can drop a schema on top of mongo >>>> and present it as rows and columns. It seems to pass the litmus test being >>>> presented. >>>> >>>> https://github.com/mongodb/mongo-hadoop/wiki/Hive-Usage >>>> >>>> >>>> >>>> >>>> >>>> On Mon, Oct 3, 2016 at 10:02 AM, Jonathan Haddad <j...@jonhaddad.com> >>>> wrote: >>>> >>>> Sorry Ed, but you're really stretching here. A table in Cassandra is >>>> structured by a schema with the data for each row stored together in each >>>> data file. Just because it uses log structured storage, sparse fields, and >>>> semi-flexible collections doesn't disqualify it from calling it a "row >>>> store" >>>> >>>> Postgres added flexible storage through hstore, I don't hear anyone >>>> arguing that it needs to be renamed. >>>> >>>> Any relational db could (and I'm sure one does!) allow for sparse >>>> fields as well. MySQL can be backed by rocksdb now, does that make it not a >>>> row store? >>>> >>>> You're arguing that everything is wrong but you're not proposing an >>>> alternative, which is not productive. >>>> On Mon, Oct 3, 2016 at 9:40 AM Edward Capriolo <edlinuxg...@gmail.com> >>>> wrote: >>>> >>>> Also every piece of techincal information that describes a rowstore >>>> >>>> http://cs-www.cs.yale.edu/homes/dna/talks/abadi-sigmod08-slides.pdf >>>> https://en.wikipedia.org/wiki/Column-oriented_DBMS#Row-oriented_systems >>>> >>>> Does it like this: >>>> >>>> 001:10,Smith,Joe,40000; >>>> 002:12,Jones,Mary,50000; >>>> 003:11,Johnson,Cathy,44000; >>>> 004:22,Jones,Bob,55000; >>>> >>>> >>>> >>>> The never depict a scenario where a the data looks like this on disk: >>>> >>>> 001:10,Smith >>>> >>>> 001:10,40000; >>>> >>>> Which is much closer to how Cassandra *stores* it's data. >>>> >>>> >>>> >>>> On Fri, Sep 30, 2016 at 5:12 PM, Benedict Elliott Smith < >>>> bened...@apache.org> wrote: >>>> >>>> Absolutely. A "partitioned row store" is exactly what I would call >>>> it. As it happens, our README thinks the same, which is fantastic. >>>> >>>> I thought I'd take a look at the rest of our cohort, and didn't get far >>>> before disappointment. HBase literally calls itself a " >>>> *column-oriented* store" - which is so totally wrong it's >>>> simultaneously hilarious and tragic. >>>> >>>> I guess we can't blame the wider internet for >>>> misunderstanding/misnaming us poor "wide column stores" if even one of the >>>> major examples doesn't know what it, itself, is! >>>> >>>> >>>> >>>> >>>> On 30 September 2016 at 21:47, Jonathan Haddad <j...@jonhaddad.com> >>>> wrote: >>>> >>>> +1000 to what Benedict says. I usually call it a "partitioned row >>>> store" which usually needs some extra explanation but is more accurate than >>>> "column family" or whatever other thrift era terminology people still use. >>>> On Fri, Sep 30, 2016 at 1:53 PM DuyHai Doan <doanduy...@gmail.com> >>>> wrote: >>>> >>>> I used to present Cassandra as a NoSQL datastore with "distributed" >>>> table. This definition is closer to CQL and has some academic background >>>> (distributed hash table). >>>> >>>> >>>> On Fri, Sep 30, 2016 at 7:43 PM, Benedict Elliott Smith < >>>> bened...@apache.org> wrote: >>>> >>>> Cassandra is not a "wide column store" anymore. It has a schema. Only >>>> thrift users no longer think they have a schema (though they do), and >>>> thrift is being deprecated. >>>> >>>> I really wish everyone would kill the term "wide column store" with >>>> fire. It seems to have never meant anything beyond "schema-less, >>>> row-oriented", and a "column store" means literally the opposite of this. >>>> >>>> Not only that, but people don't even seem to realise the term "column >>>> store" existed long before "wide column store" and the latter is often >>>> abbreviated to the former, as here: http://www.planetcassandra.org >>>> /what-is-nosql/ >>>> >>>> Since it no longer applies, let's all agree as a community to forget >>>> this awful nomenclature ever existed. >>>> >>>> >>>> >>>> On 30 September 2016 at 18:09, Joaquin Casares < >>>> joaq...@thelastpickle.com> wrote: >>>> >>>> Hi Mehdi, >>>> >>>> I can help clarify a few things. >>>> >>>> As Carlos said, Cassandra is a Wide Column Store. Theoretically a row >>>> can have 2 billion columns, but in practice it shouldn't have more than 100 >>>> million columns. >>>> >>>> Cassandra partitions data to certain nodes based on the partition >>>> key(s), but does provide the option of setting zero or more clustering >>>> keys. Together, the partition key(s) and clustering key(s) form the primary >>>> key. >>>> >>>> When writing to Cassandra, you will need to provide the full primary >>>> key, however, when reading from Cassandra, you only need to provide the >>>> full partition key. >>>> >>>> When you only provide the partition key for a read operation, you're >>>> able to return all columns that exist on that partition with low latency. >>>> These columns are displayed as "CQL rows" to make it easier to reason >>>> about. >>>> >>>> Consider the schema: >>>> >>>> CREATE TABLE foo ( >>>> bar uuid, >>>> >>>> boz uuid, >>>> >>>> baz timeuuid, >>>> data1 text, >>>> >>>> data2 text, >>>> >>>> PRIMARY KEY ((bar, boz), baz) >>>> >>>> ); >>>> >>>> >>>> When you write to Cassandra you will need to send bar, boz, and baz and >>>> optionally data*, if it's relevant for that CQL row. If you chose not to >>>> define a data* field for a particular CQL row, then nothing is stored nor >>>> allocated on disk. But I wouldn't consider that caveat to be "schema-less". >>>> >>>> However, all writes to the same bar/boz will end up on the same >>>> Cassandra replica set (a configurable number of nodes) and be stored on the >>>> same place(s) on disk within the SSTable(s). And on disk, each field that's >>>> not a partition key is stored as a column, including clustering keys (this >>>> is optimized in Cassandra 3+, but now we're getting deep into internals). >>>> >>>> In this way you can get fast responses for all activity for bar/boz >>>> either over time, or for a specific time, with roughly the same number of >>>> disk seeks, with varying lengths on the disk scans. >>>> >>>> Hope that helps! >>>> >>>> Joaquin Casares >>>> Consultant >>>> Austin, TX >>>> >>>> Apache Cassandra Consulting >>>> http://www.thelastpickle.com >>>> >>>> On Fri, Sep 30, 2016 at 11:40 AM, Carlos Alonso <i...@mrcalonso.com> >>>> wrote: >>>> >>>> Cassandra is a Wide Column Store http://db-engines.com/en >>>> /system/Cassandra >>>> >>>> Carlos Alonso | Software Engineer | @calonso >>>> <https://twitter.com/calonso> >>>> >>>> On 30 September 2016 at 18:24, Mehdi Bada <mehdi.b...@dbi-services.com> >>>> wrote: >>>> >>>> Hi all, >>>> >>>> I have a theoritical question: >>>> - Is Apache Cassandra really a column store? >>>> Column store mean storing the data as column rather than as a rows. >>>> >>>> In fact C* store the data as row, and data is partionned with row key. >>>> >>>> Finally, for me, Cassandra is a row oriented schema less DBMS.... Is it >>>> true for you also??? >>>> >>>> Many thanks in advance for your reply >>>> >>>> Best Regards >>>> Mehdi Bada >>>> ---- >>>> >>>> *Mehdi Bada* | Consultant >>>> Phone: +41 32 422 96 00 | Mobile: +41 79 928 75 48 | Fax: +41 32 422 >>>> 96 15 >>>> dbi services, Rue de la Jeunesse 2, CH-2800 Delémont >>>> mehdi.b...@dbi-services.com >>>> www.dbi-services.com >>>> >>>> >>>> >>>> >>>> *⇒ dbi services is recruiting Oracle & SQL Server experts ! – Join the >>>> team >>>> <http://www.dbi-services.com/fr/dbi-services-et-ses-collaborateurs/offres-emplois-opportunites-carrieres/>* >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >> >
