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Questions tagged [wide-column-store]

A wide column store is a type of key-value database. It uses tables, rows, and columns, but unlike a relational database, the names and format of the columns can vary from row to row in the same table.

Wide column store refers to databases like Apache Cassandra, Apache HBase, Apache Accumulo, Hypertable or Sqrrl. Databases good to store sparse table data.

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Why many refer to Cassandra as a Column oriented database?

Reading several papers and documents on internet, I found many contradictory information about the Cassandra data model. There are many which identify it as a column oriented database, other as a row-oriented and then who define it as a hybrid way…
cesare
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What exactly is a wide column store?

Googling for a definition either returns results for a column oriented DB or gives very vague definitions. My understanding is that wide column stores consist of column families which consist of rows and columns. Each row within said family is…
Dennis Subachev
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Is Cassandra a column oriented or columnar database

Columnar database should store group of columns together. But Cassandra stores data row-wise. SS Table will hold multiple rows of data mapped to their corresponding partition key. So I feel like Cassandra is a row wise data store like MySQL but has…
saktheesh kumarraja
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Comparing Cassandra structure with Relational Databases

A few days ago I read about wide-column stored type of NoSQL and exclusively Apache-Cassandra. What I understand is that Cassandra consist of: A keyspace(like database in relational databases) and supporting many column families or tables (Same as…
Mohammad Sina Karvandi
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Wide column vs column family vs columnar vs column oriented DB definition

There are lots of confusions among these terms. I'd like to through my understanding out and see if people agree. I have seen conflicting and wrong definition all over the web. In my mind, wide column and column family DB are essentially the same…
Kenneth
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Wide data frame with 4 columns to long data frame with 3 columns

I have a data frame (sample below), as follows: df = structure(list(Stage1yBefore = c("3.1", "1", "4", "2", "NA"), Stage2yBefore = c("NA", "2", "3.2", "2", "NA"), ClinicalActivity1yBefore = c(TRUE, TRUE, TRUE, TRUE, FALSE),…
Omry Atia
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Key-Value vs Wide-Column DB

I want to know what is the difference between a persistent key-value DB and a wide-column DB. I understand in both DBs you retrieve a single value by a key, so what is the difference between the types of the values? Thanks!
Forepick
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wide vs long format when saving data in pandas hdf5

pandas data frame are in general represented in long ( a lot of rows) or wide (a lot of columns) format. I'm wondering which format is faster to read and occupies less memory when saved as hdf file (df.to_hdf). Is there a general rule or some…
Donbeo
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Transforming Wide for Long Database, Grouping Variables in R

I would like to make a modification to my database. What I am trying to do is transform every row of my database being for a single individual. database:https://drive.google.com/open?id=1HBigWWspksM6Pz3X_IFYBVN-HCED1YGu I want it to look like this.…
Breno S.
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On Cassandra how to enable LDAP authentication

I have a Cassandra cluster running on Ubuntu. I would like to enable authentication so that not everyone will have access to the Cassandra database and run queries. Enabling simple authentication is available at…
Kumar
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filter for key-value pair in cassandra wide rows

I am trying to model time series data with many sensors (> 50k) with cassandra. As I would like to do filtering on multiple sensors at the same time, I thought using the following (wide row) schema might be suitable: CREATE TABLE data( time…
Calardan
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Is it a correct pattern to build composite primary key using wide columns stores?

HBase and Cassandra are built as wide column stores, using the concepts of both rows and columns. A row is composed of a key similar to the concept of primary key in RDBMS and a value composed of several columns A representation can be the…
amirouche
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R dataset from long to wide - under a specific condition

I want to transform a long and chronological dataset into a wide but chronological dataset by ID Let's see an example: ID Product Date 1 Bike 1/1/2000 1 Tire 2/1/2000 2 Car 15/2/2000 2 Seat 17/2/2000 1 Chronometer 20/2/2000 Into…
andre macedo costa
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How to change from Long format to Wide format?

I want to convert my data frame in long format to a data frame with wide format. So far I could be able to find the function reshape to make this transformation, neverthless this my result. df id | state | homicides |…
coding
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is a column family placed one next to the other on disk in HBase? another words, is HBase Column-oriented?

I'm trying to understand if HBase is a Column-oriented DB. I understand the structure of one row of HBase - it is divided into column families(which are static and don't change) and each column family can have dynamic number of columns: row:…
nadavgam
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