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".
Questions tagged [column-family]
71 questions
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Truncate/Delete all the columns except one from the Cassandra
I have a column family like this -
create column family TEST
with key_validation_class = 'UTF8Type'
and comparator = 'UTF8Type'
and default_validation_class = 'UTF8Type'
and column_metadata = [ {column_name : 'date', validation_class :…
AKIWEB
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Cassandra column family for different data types
Below is the data which I need to represent in my Cassandra Column Family.
rowKey e1_name e1_schemaname e1_last_modified_date
123 (ByteArray value) abc (some string) …
arsenal
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Group three columns value into one colum in Cassandra?
Below is the data which I need to represent in my Cassandra Column Family.
rowKey e1_name e1_schemaname e1_last_modified_date
123 (ByteArray value) abc (some string) …
arsenal
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3 answers
Composite Column Values in Cassandra?
Can we have a composite values in each columns in Cassandra Column Family?
user-id column1-name
123 (Column1-Value Column1-SchemaName Column1-LastModifiedDate)
userId is the rowKey here. And same thing will be for other columns as…
arsenal
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1 answer
InvalidRequestException while inserting into Composite Columns using Astyanax
I am tyring to insert into Composite Column in Cassandra column family using Astyanax client. Each column will be a composite column meaning its value will be made of three values as shown in my ComplexType class. Below is my column family in…
arsenal
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RuntimeException: Unknown comparator 'CompositeType'
I need to create CompositeColumns in a Cassandra ColumnFamily.
Each column value will store the something like this-
user-id column1
123 (Column1-Value Column1-SchemaName LastModifiedDate)
same with column2 as well and other columns as…
AKIWEB
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How to understand CQL3 table model from scratch?
I recently visited http://cassandra.apache.org/doc/cql3/CQL.html#CQLSyntax and just read this:
[...] please note that as such, they do not refer to the concept of
rows and columns found in the internal implementation of Cassandra and
in the…
Abu Abuu
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2 answers
How To Change the replication of a Column family in HBase
The question is mainly about that, in my project, I want to create a table with 3 column family. the default replication number is 3. but I wanna change this replication number for centain column family, just because we dont need so much repliction…
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1 answer
HBASE: Column Family related operations, after the fact?
Is there a way to split out a column family into multiple families - after the fact - in HBase?
This is clearly a bad idea, but in some cases it might be worthwhile, i.e.
1) if you have enough time to take your HBase server offline and see an…
jayunit100
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Real world use cases of nosql database types
Could please someone helip me with a real world application of each nosql database types?
(graph, key-value stores, column-family, document)
Thanks in advance!
lse23
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How to understand the concept of wide row and related concepts in Cassandra?
I feel very difficult to understand the concept of wide row and related concepts from Cassandra The Definite Guide:
Cassandra uses a special primary key called a composite key (or compound key) to
represent wide rows, also called partitions. The…
Tim
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