Does the array have to be a KEY?
Sorry I don't understand this question.
In the samples you give you specify array as
CREATE COLUMNFAMILY Description (
PRIMARY_KEY
(vector_name, index),
Age text,
Gender text,
vector_name text,
index bigint,
...
Or
CREATE COLUMNFAMILY Description (
PRIMARY_KEY
(listr_name, sort_key),
Age text,
Gender text,
sort_key bigint,
list_name text
..
In both cases the array is the PRIMARY_KEY. In order for an array to work
does the array have to be a KEY?
From: aaron morton [mailto:[email protected]]
Sent: Tuesday, November 13, 2012 10:18 PM
To: [email protected]
Subject: Re: CF metadata syntax for an array
Would this syntax be the same for CREATE COLUMNFAMILY (as an aside what is a
'TABLE' in Cassandra)?
Yes, CQL 2 uses COLUMN FAMILY or Table and CQL 3 uses TABLE
http://www.datastax.com/dev/blog/cql3-evolutions
In other words is this valid:
Does it work ? Is so it's valid.
Does the array have to be a KEY?
Sorry I don't understand this question.
Finally, what would be the syntax for inserting data into the CF?
Depends on what you want to do.
Docs are a good starting point
http://www.datastax.com/docs/1.1/references/cql/index
Cheers
-----------------
Aaron Morton
Freelance Developer
@aaronmorton
http://www.thelastpickle.com
On 14/11/2012, at 2:42 AM, Kevin Burton <[email protected]> wrote:
Sorry to be so slow but I am just learning CQL. Would this syntax be the
same for CREATE COLUMNFAMILY (as an aside what is a 'TABLE' in Cassandra)?
In other words is this valid:
CREATE COLUMNFAMILY Description (
PRIMARY_KEY
(vector_name, index),
Age text,
Gender text,
vector_name text,
index bigint,
...
Or
CREATE COLUMNFAMILY Description (
PRIMARY_KEY
(listr_name, sort_key),
Age text,
Gender text,
sort_key bigint,
list_name text
..
Does the array have to be a KEY? Finally, what would be the syntax for
inserting data into the CF?
Thanks again.
From: aaron morton [mailto:[email protected]]
Sent: Tuesday, November 13, 2012 4:09 AM
To: [email protected]
Subject: Re: CF metadata syntax for an array
While this solves the problem for an array of 'primitive' types. What if I
want an array or collection of an arbitrary type like list<foo>, where foo
is a user defined type?
Do you mean a custom Cassandra data type that sub classes AbstractType? I
dont think CQL can support those, I may be wrong though.
If you mean a basic client side data type you could serialise it and store
as a string or byte buffer in a CQL collection.
What are the options to solve this type of array?
...
arbitrary type like list<foo>,
Do you mean an array such as int[] or do you mean the equivalent of a java
List<T> with functions like remove that actually delete items and from the
list?
If it's the former a CQL table such as below would work
CREATE TABLE vectors (
vector_name text,
index bigint,
object_property_1 text,
object_property_2 text,
PRIMARY_KEY (vector_name, index)
);
The problem is, if you delete a element at (vector, index) the remaining
indexes will be off.
If it's the later, a List<T>, then it depends a little on what features you
want to support. If you want a sorted list of objects the table is roughly
the same
CREATE TABLE List (
list_name text,
sort_key bigint,
object_property_1 text,
object_property_2 text,
PRIMARY_KEY (list_name, sort_key)
);
Hope that helps.
-----------------
Aaron Morton
Freelance Developer
@aaronmorton
<http://www.thelastpickle.com> http://www.thelastpickle.com
-----------------
Aaron Morton
Freelance Developer
@aaronmorton
<http://www.thelastpickle.com> http://www.thelastpickle.com
On 13/11/2012, at 9:46 AM, Kevin Burton < <mailto:[email protected]>
[email protected]> wrote:
While this solves the problem for an array of 'primitive' types. What if I
want an array or collection of an arbitrary type like list<foo>, where foo
is a user defined type? I am guessing that this cannot be done with
'collections'. What are the options to solve this type of array?
On Nov 12, 2012, at 2:28 PM, aaron morton < <mailto:[email protected]>
[email protected]> wrote:
This may help <http://www.datastax.com/dev/blog/cql3_collections>
http://www.datastax.com/dev/blog/cql3_collections
I have gotten as far as feeling a need to understand a 'super-column'
You can happily ignore them.
Cheers
-----------------
Aaron Morton
Freelance Developer
@aaronmorton
<http://www.thelastpickle.com/> http://www.thelastpickle.com
On 12/11/2012, at 8:35 PM, Kevin Burton < <mailto:[email protected]>
[email protected]> wrote:
I am sorry if this is an FAQ. But I was wondering what the syntax for
describing an array? I have gotten as far as feeling a need to understand a
'super-column' but I fail after that. Once I have the metadata in place to
describe an array how do I insert data into the array? Get data from the
array? Thank you.
