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Questions tagged [column-family]

A column family is a NoSQL object that contains columns of related data. It is a tuple (pair) that consists of a key-value pair, where the key is mapped to a value that is a set of columns. In analogy with relational databases, a column family is as a "table".

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Cassandra has a limit of 2 billion cells per partition, but what's a partition?

In Cassandra Wiki, it is said that there is a limit of 2 billion cells (rows x columns) per partition. But it is unclear to me what is a partition? Do we have one partition per node per column family, which would mean that the max size of a column…
Benoit Thiery
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How to add new column family to an existing HBase table?

I created a table by create 'tablename', 'columnfamily1' Now is it possible to add another column family 'columnfamily2'? What is the method?
proutray
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Wide column vs column family vs columnar vs column oriented DB definition

There's a lot of confusion among these terms. I'd like to throw my understanding out and see if people agree. I have seen conflicting and wrong definitions all over the web. In my mind, wide column and column family DBs are essentially the same…
Kenneth
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What NoSQL database (categories) support versioning?

I thought that regardless of whether a NoSQL aggregate store is a key-value, column-family or document database, it would support versioning of values. After a bit of Googling, I'm concluding that this assumption is wrong and that it just depends on…
Sridhar Sarnobat
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how to get value from counter Column in cassandra with multiple row keys?

I have one column family that has multiple counter columns. Now I want to get their value behalf of different row keys, Means like RangeSlicesQuery or MultigetSliceQuery, I want to apply on counter column please give me way in counter column.
Rohit Sharma
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How to trace back a large partition of a column family in cassandra

Through ops-center and nodetool cfstats i was able to find that one of the partitions of a keyspace table is 560 Mb, but couldn't find out which partition is that. How can we trace which partition of the table is that big ??
user6288321
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Why do we need column families in Hbase?

What is the reason for having column families? Example: Scenario 1 : Table Row-Key ColumnFamily1 ColumnFamily2 ColumnFamily3 Scenario 2 : Table1 Row-Key Column1...ColumnN Table2 Row-Key Column1...ColumnN Table3 Row-Key Column1...ColumnN In…
user12318711
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Why does HBase need to store the Column Family for every Value?

Because HBase tables are sparse tables, HBase stores for every cell not only the value, but all the information required to identify the cell (often described as the Key, not to be confused with the RowKey). The Key looks as…
user3793764
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Columnar/Column-oriented database vs wide-column/column family database

I got really confused about Cassandra recently because most online material even AWS and Google describe it as columnar database. But actually it is row-based, partitioned, column-family database. Now everything makes sense to me: Then are all…
Stan
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How to insert in Cassandra into Composite Columns using Astyanax client?

I am trying to insert into Composite Columns in Cassandra using Astyanax client. Below is the column family I have created in which all the columns are Composite Columns. I am not sure how should I insert into below Column Family with each columns…
arsenal
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Cassandra dynamic column family

I am new to cassandra and I read some articles about static and dynamic column family. It is mentioned ,From Cassandra 3 table and column family are same. I created key space, some tables and inserted data into that table. CREATE TABLE subscribers( …
Manzoor
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Hbase table column value not able to update- if variable having NaN

I am not able to update the value in hbase column family. The condition is - If variable cricketScore is not a number then update the value as "NA", otherwise update the value. cricketScore= 100F // isNaN -- > false // cricketScore = 0.0/0.0 …
santhosh raj
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cassandra cqlsh data format issue

I have an operational cassandra cluster with the tarball installation of apache Cassandra 3.7 in a single data center mode. CQLSH Issue: When I describe the column family I see the column names are correctly shown but when I do a select on the table…
shravan
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Cassandra Time Series Data Modelling and Limiting Partition Size

We are currently investigating Cassandra as the database for a large time series system. I have read through https://academy.datastax.com/resources/getting-started-time-series-data-modeling about modelling time series data in Cassandra. What we have…
dacox
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How we can do CRUD operations on complex data models in Cassandra?

How we can do CRUD operations on complex data models in Cassandra? I have a project using NOSQL. I have a column family for my customers. The column family has just "id" at first. Then it will be updated by altering new columns. Count and type…
Elnaz
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