Re: Storing values of mixed types in a list
Unfortunately, I need to query per list items. That's why I'm running
Cassandra 2.1rc1 (offers secondary indexes for collections).
I'm also studying Dynamo, it seems to be somewhat more dynamic by nature
and allows mixed type lists. As I understood it, also Cassandra supports
dynamic schemas, but only through Thrift protocol. Also, I don't think it
changes the fact that collections need to be strongly-typed in Cassandra,
no matter what protocol is used?
Tuukka
On Tue, Jun 24, 2014 at 9:41 PM, DuyHai Doan doanduy...@gmail.com wrote:
Jeremy, with blob field (ByteBuffer), I can query exact matches (just
encode the value in query), but greater/less than queries would not work.
Any sort of serialization kills native ways to query data -- Not
necessarily. You still use normal types (uuid, string, timestamp,...) for
clustering columns and use them for querying. For the cells where you store
values, use blob type.
On Tue, Jun 24, 2014 at 8:21 PM, Tuukka Mustonen
tuukka.musto...@gmail.com wrote:
What if I need to query by list items?
1. Jeremy, with blob field (ByteBuffer), I can query exact matches (just
encode the value in query), but greater/less than queries would not work.
Any sort of serialization kills native ways to query data
2. Even with user defined types, I would need to define separate fields
for each value. Running queries would be cumbersome (something like WHERE
items CONTAINS {'text_value': 'foobar'} or WHERE items CONTAINS
{'int_value': 3}. Pavel, did you mean like this?
I'm running 2.1rc1 with python driver 2.0.2.
Tuukka
On Tue, Jun 24, 2014 at 4:39 PM, Pavel Kogan pavel.ko...@cortica.com
wrote:
1) You can use list of strings which are serialized JSONs, or use
ByteBuffer with your own serialization as Jeremy suggested.
2) Use Cassandra 2.1 (not officially released yet) were there is new
feature of user defined types.
Pavel
On Tue, Jun 24, 2014 at 9:18 AM, Jeremy Jongsma jer...@barchart.com
wrote:
Use a ByteBuffer value type with your own serialization (we use
protobuf for complex value structures)
On Jun 24, 2014 5:30 AM, Tuukka Mustonen tuukka.musto...@gmail.com
wrote:
Hello,
I need to store a list of mixed types in Cassandra. The list may
contain numbers, strings and booleans. So I would need something like
list?.
Is this possible in Cassandra and if not, what workaround would you
suggest for storing a list of mixed type items? I sketched a few (using a
list per type, using list of user types in Cassandra 2.1, etc.), but I get
a bad feeling about each.
Couldn't find an exact answer to this through searches...
Regards,
Tuukka
P.S. I first asked this at SO before realizing the traffic there is
very low:
http://stackoverflow.com/questions/24380158/storing-a-list-of-mixed-types-in-cassandra
Re: Storing values of mixed types in a list
On Wed, Jun 25, 2014 at 8:49 AM, Tuukka Mustonen tuukka.musto...@gmail.com
wrote:
Unfortunately, I need to query per list items. That's why I'm running
Cassandra 2.1rc1 (offers secondary indexes for collections).
Using a list of blobs does not in any way prevent you from doing that.
Types are constraints on what values C* will accept and using blob is
simply asking C* to not reject any value. Doing so does not in any way
limit the kind of queries you can do.
The small downside of using blobs is that you'll have to
serialize/deserialize your value manually client-side, but that's not a
huge deal either. That said, if you really only have 3 types of values to
store and if you don't particularly care about the order of items in the
collection (i.e. if you said you want a list but could really do with a
set), then storing 3 different sets can be a viable solution too (as in,
there is no strong downside to doing it as far as C* is concerned and it
may be simpler to deal with client side (or not, it depends a bit on what
your client side code does exactly)).
As I understood it, also Cassandra supports dynamic schemas, but only
through Thrift protocol.
dynamic schemas is a terribly imprecise term that means different things
to different people, but in general that statement is incorrect: you can do
the same things with CQL and with Thrift.
Also, I don't think it changes the fact that collections need to be
strongly-typed in Cassandra, no matter what protocol is used?
Well, yes since you do have to provide a type for the elements in the
collection, but as said previously that does not in any way prevent you for
having collections of anything since you can use a blob type.
--
Sylvain
Tuukka
On Tue, Jun 24, 2014 at 9:41 PM, DuyHai Doan doanduy...@gmail.com wrote:
Jeremy, with blob field (ByteBuffer), I can query exact matches (just
encode the value in query), but greater/less than queries would not work.
Any sort of serialization kills native ways to query data -- Not
necessarily. You still use normal types (uuid, string, timestamp,...) for
clustering columns and use them for querying. For the cells where you store
values, use blob type.
On Tue, Jun 24, 2014 at 8:21 PM, Tuukka Mustonen
tuukka.musto...@gmail.com wrote:
What if I need to query by list items?
1. Jeremy, with blob field (ByteBuffer), I can query exact matches (just
encode the value in query), but greater/less than queries would not work.
Any sort of serialization kills native ways to query data
2. Even with user defined types, I would need to define separate fields
for each value. Running queries would be cumbersome (something like WHERE
items CONTAINS {'text_value': 'foobar'} or WHERE items CONTAINS
{'int_value': 3}. Pavel, did you mean like this?
I'm running 2.1rc1 with python driver 2.0.2.
Tuukka
On Tue, Jun 24, 2014 at 4:39 PM, Pavel Kogan pavel.ko...@cortica.com
wrote:
1) You can use list of strings which are serialized JSONs, or use
ByteBuffer with your own serialization as Jeremy suggested.
2) Use Cassandra 2.1 (not officially released yet) were there is new
feature of user defined types.
Pavel
On Tue, Jun 24, 2014 at 9:18 AM, Jeremy Jongsma jer...@barchart.com
wrote:
Use a ByteBuffer value type with your own serialization (we use
protobuf for complex value structures)
On Jun 24, 2014 5:30 AM, Tuukka Mustonen tuukka.musto...@gmail.com
wrote:
Hello,
I need to store a list of mixed types in Cassandra. The list may
contain numbers, strings and booleans. So I would need something like
list?.
Is this possible in Cassandra and if not, what workaround would you
suggest for storing a list of mixed type items? I sketched a few (using a
list per type, using list of user types in Cassandra 2.1, etc.), but I
get
a bad feeling about each.
Couldn't find an exact answer to this through searches...
Regards,
Tuukka
P.S. I first asked this at SO before realizing the traffic there is
very low:
http://stackoverflow.com/questions/24380158/storing-a-list-of-mixed-types-in-cassandra
Re: Storing values of mixed types in a list
Sorry for confusion, I should have lined my requirements better in the
first place. Let me try to summarize:
- I can use listblob and query against it using secondary indexes and by
encoding my data on the client side. However, *this only allows exact
matches, not greater/lesser than *for numbers at least (not sure I need to,
but maybe). Please correct me if I got it wrong? I'm not very familiar with
playing with binary.
- My supported list of types is very limited, indeed, and the order doesn't
matter, so I could use separate list for each type. However, that makes
playing with data somewhat cumbersome and I need to have multiple clauses
in queries then, for each type.
- I could use user defined types, but I would still have to define separate
field for each value and queries would again be cumbersome.
Let's forget about dynamic schema as I'm a Cassandra newbie and
definitively need to study more before opening that chest of wonders.
Thanks for correcting me.
I just wish there was an easy way to define a list as list? and to run
queries against. But, sounds like there isn't (and nobody is seeing need
for it) so I think I'll just take one of the suggested workarounds...
Tuukka
On Wed, Jun 25, 2014 at 10:47 AM, Sylvain Lebresne sylv...@datastax.com
wrote:
On Wed, Jun 25, 2014 at 8:49 AM, Tuukka Mustonen
tuukka.musto...@gmail.com wrote:
Unfortunately, I need to query per list items. That's why I'm running
Cassandra 2.1rc1 (offers secondary indexes for collections).
Using a list of blobs does not in any way prevent you from doing that.
Types are constraints on what values C* will accept and using blob is
simply asking C* to not reject any value. Doing so does not in any way
limit the kind of queries you can do.
The small downside of using blobs is that you'll have to
serialize/deserialize your value manually client-side, but that's not a
huge deal either. That said, if you really only have 3 types of values to
store and if you don't particularly care about the order of items in the
collection (i.e. if you said you want a list but could really do with a
set), then storing 3 different sets can be a viable solution too (as in,
there is no strong downside to doing it as far as C* is concerned and it
may be simpler to deal with client side (or not, it depends a bit on what
your client side code does exactly)).
As I understood it, also Cassandra supports dynamic schemas, but only
through Thrift protocol.
dynamic schemas is a terribly imprecise term that means different things
to different people, but in general that statement is incorrect: you can do
the same things with CQL and with Thrift.
Also, I don't think it changes the fact that collections need to be
strongly-typed in Cassandra, no matter what protocol is used?
Well, yes since you do have to provide a type for the elements in the
collection, but as said previously that does not in any way prevent you for
having collections of anything since you can use a blob type.
--
Sylvain
Tuukka
On Tue, Jun 24, 2014 at 9:41 PM, DuyHai Doan doanduy...@gmail.com
wrote:
Jeremy, with blob field (ByteBuffer), I can query exact matches (just
encode the value in query), but greater/less than queries would not work.
Any sort of serialization kills native ways to query data -- Not
necessarily. You still use normal types (uuid, string, timestamp,...) for
clustering columns and use them for querying. For the cells where you store
values, use blob type.
On Tue, Jun 24, 2014 at 8:21 PM, Tuukka Mustonen
tuukka.musto...@gmail.com wrote:
What if I need to query by list items?
1. Jeremy, with blob field (ByteBuffer), I can query exact matches
(just encode the value in query), but greater/less than queries would not
work. Any sort of serialization kills native ways to query data
2. Even with user defined types, I would need to define separate fields
for each value. Running queries would be cumbersome (something like WHERE
items CONTAINS {'text_value': 'foobar'} or WHERE items CONTAINS
{'int_value': 3}. Pavel, did you mean like this?
I'm running 2.1rc1 with python driver 2.0.2.
Tuukka
On Tue, Jun 24, 2014 at 4:39 PM, Pavel Kogan pavel.ko...@cortica.com
wrote:
1) You can use list of strings which are serialized JSONs, or use
ByteBuffer with your own serialization as Jeremy suggested.
2) Use Cassandra 2.1 (not officially released yet) were there is new
feature of user defined types.
Pavel
On Tue, Jun 24, 2014 at 9:18 AM, Jeremy Jongsma jer...@barchart.com
wrote:
Use a ByteBuffer value type with your own serialization (we use
protobuf for complex value structures)
On Jun 24, 2014 5:30 AM, Tuukka Mustonen
tuukka.musto...@gmail.com wrote:
Hello,
I need to store a list of mixed types in Cassandra. The list may
contain numbers, strings and booleans. So I would need something like
list?.
Is this possible in Cassandra and if not, what workaround would you
suggest for storing a
Re: Storing values of mixed types in a list
Actually, come to think of it, of course I cannot run greater/less than
queries on list items anyway (would be something like WHERE items CONTAINS
4), so binary encoding should be fine. Thanks for everybody's input!
Tuukka
On Wed, Jun 25, 2014 at 1:49 PM, Tuukka Mustonen tuukka.musto...@gmail.com
wrote:
Sorry for confusion, I should have lined my requirements better in the
first place. Let me try to summarize:
- I can use listblob and query against it using secondary indexes and by
encoding my data on the client side. However, *this only allows exact
matches, not greater/lesser than *for numbers at least (not sure I need
to, but maybe). Please correct me if I got it wrong? I'm not very familiar
with playing with binary.
- My supported list of types is very limited, indeed, and the order
doesn't matter, so I could use separate list for each type. However, that
makes playing with data somewhat cumbersome and I need to have multiple
clauses in queries then, for each type.
- I could use user defined types, but I would still have to define
separate field for each value and queries would again be cumbersome.
Let's forget about dynamic schema as I'm a Cassandra newbie and
definitively need to study more before opening that chest of wonders.
Thanks for correcting me.
I just wish there was an easy way to define a list as list? and to run
queries against. But, sounds like there isn't (and nobody is seeing need
for it) so I think I'll just take one of the suggested workarounds...
Tuukka
On Wed, Jun 25, 2014 at 10:47 AM, Sylvain Lebresne sylv...@datastax.com
wrote:
On Wed, Jun 25, 2014 at 8:49 AM, Tuukka Mustonen
tuukka.musto...@gmail.com wrote:
Unfortunately, I need to query per list items. That's why I'm running
Cassandra 2.1rc1 (offers secondary indexes for collections).
Using a list of blobs does not in any way prevent you from doing that.
Types are constraints on what values C* will accept and using blob is
simply asking C* to not reject any value. Doing so does not in any way
limit the kind of queries you can do.
The small downside of using blobs is that you'll have to
serialize/deserialize your value manually client-side, but that's not a
huge deal either. That said, if you really only have 3 types of values to
store and if you don't particularly care about the order of items in the
collection (i.e. if you said you want a list but could really do with a
set), then storing 3 different sets can be a viable solution too (as in,
there is no strong downside to doing it as far as C* is concerned and it
may be simpler to deal with client side (or not, it depends a bit on what
your client side code does exactly)).
As I understood it, also Cassandra supports dynamic schemas, but only
through Thrift protocol.
dynamic schemas is a terribly imprecise term that means different
things to different people, but in general that statement is incorrect: you
can do the same things with CQL and with Thrift.
Also, I don't think it changes the fact that collections need to be
strongly-typed in Cassandra, no matter what protocol is used?
Well, yes since you do have to provide a type for the elements in the
collection, but as said previously that does not in any way prevent you for
having collections of anything since you can use a blob type.
--
Sylvain
Tuukka
On Tue, Jun 24, 2014 at 9:41 PM, DuyHai Doan doanduy...@gmail.com
wrote:
Jeremy, with blob field (ByteBuffer), I can query exact matches (just
encode the value in query), but greater/less than queries would not work.
Any sort of serialization kills native ways to query data -- Not
necessarily. You still use normal types (uuid, string, timestamp,...) for
clustering columns and use them for querying. For the cells where you store
values, use blob type.
On Tue, Jun 24, 2014 at 8:21 PM, Tuukka Mustonen
tuukka.musto...@gmail.com wrote:
What if I need to query by list items?
1. Jeremy, with blob field (ByteBuffer), I can query exact matches
(just encode the value in query), but greater/less than queries would not
work. Any sort of serialization kills native ways to query data
2. Even with user defined types, I would need to define separate
fields for each value. Running queries would be cumbersome (something like
WHERE items CONTAINS {'text_value': 'foobar'} or WHERE items CONTAINS
{'int_value': 3}. Pavel, did you mean like this?
I'm running 2.1rc1 with python driver 2.0.2.
Tuukka
On Tue, Jun 24, 2014 at 4:39 PM, Pavel Kogan pavel.ko...@cortica.com
wrote:
1) You can use list of strings which are serialized JSONs, or use
ByteBuffer with your own serialization as Jeremy suggested.
2) Use Cassandra 2.1 (not officially released yet) were there is new
feature of user defined types.
Pavel
On Tue, Jun 24, 2014 at 9:18 AM, Jeremy Jongsma jer...@barchart.com
wrote:
Use a ByteBuffer value type with your own serialization (we use
protobuf for complex value
Re: Storing values of mixed types in a list
On Tue, Jun 24, 2014 at 11:49 PM, Tuukka Mustonen tuukka.musto...@gmail.com wrote: Unfortunately, I need to query per list items. That's why I'm running Cassandra 2.1rc1 (offers secondary indexes for collections). As a general statement, if you have to use a just added feature in a pre-release version of the Datastore to model your problem, you may be Doing It Wrong. As I understood it, also Cassandra supports dynamic schemas, but only through Thrift protocol. Also, I don't think it changes the fact that collections need to be strongly-typed in Cassandra, no matter what protocol is used? There is an E-A-V scheme within CQL which, if you squint your eyes and click your heels three times, looks like what ppl think of when they think of dynamic schema. =Rob
Re: Storing values of mixed types in a list
Use a ByteBuffer value type with your own serialization (we use protobuf for complex value structures) On Jun 24, 2014 5:30 AM, Tuukka Mustonen tuukka.musto...@gmail.com wrote: Hello, I need to store a list of mixed types in Cassandra. The list may contain numbers, strings and booleans. So I would need something like list?. Is this possible in Cassandra and if not, what workaround would you suggest for storing a list of mixed type items? I sketched a few (using a list per type, using list of user types in Cassandra 2.1, etc.), but I get a bad feeling about each. Couldn't find an exact answer to this through searches... Regards, Tuukka P.S. I first asked this at SO before realizing the traffic there is very low: http://stackoverflow.com/questions/24380158/storing-a-list-of-mixed-types-in-cassandra
Re: Storing values of mixed types in a list
1) You can use list of strings which are serialized JSONs, or use ByteBuffer with your own serialization as Jeremy suggested. 2) Use Cassandra 2.1 (not officially released yet) were there is new feature of user defined types. Pavel On Tue, Jun 24, 2014 at 9:18 AM, Jeremy Jongsma jer...@barchart.com wrote: Use a ByteBuffer value type with your own serialization (we use protobuf for complex value structures) On Jun 24, 2014 5:30 AM, Tuukka Mustonen tuukka.musto...@gmail.com wrote: Hello, I need to store a list of mixed types in Cassandra. The list may contain numbers, strings and booleans. So I would need something like list?. Is this possible in Cassandra and if not, what workaround would you suggest for storing a list of mixed type items? I sketched a few (using a list per type, using list of user types in Cassandra 2.1, etc.), but I get a bad feeling about each. Couldn't find an exact answer to this through searches... Regards, Tuukka P.S. I first asked this at SO before realizing the traffic there is very low: http://stackoverflow.com/questions/24380158/storing-a-list-of-mixed-types-in-cassandra
Re: Storing values of mixed types in a list
What if I need to query by list items?
1. Jeremy, with blob field (ByteBuffer), I can query exact matches (just
encode the value in query), but greater/less than queries would not work.
Any sort of serialization kills native ways to query data
2. Even with user defined types, I would need to define separate fields for
each value. Running queries would be cumbersome (something like WHERE items
CONTAINS {'text_value': 'foobar'} or WHERE items CONTAINS {'int_value': 3}.
Pavel, did you mean like this?
I'm running 2.1rc1 with python driver 2.0.2.
Tuukka
On Tue, Jun 24, 2014 at 4:39 PM, Pavel Kogan pavel.ko...@cortica.com
wrote:
1) You can use list of strings which are serialized JSONs, or use
ByteBuffer with your own serialization as Jeremy suggested.
2) Use Cassandra 2.1 (not officially released yet) were there is new
feature of user defined types.
Pavel
On Tue, Jun 24, 2014 at 9:18 AM, Jeremy Jongsma jer...@barchart.com
wrote:
Use a ByteBuffer value type with your own serialization (we use protobuf
for complex value structures)
On Jun 24, 2014 5:30 AM, Tuukka Mustonen tuukka.musto...@gmail.com
wrote:
Hello,
I need to store a list of mixed types in Cassandra. The list may contain
numbers, strings and booleans. So I would need something like list?.
Is this possible in Cassandra and if not, what workaround would you
suggest for storing a list of mixed type items? I sketched a few (using a
list per type, using list of user types in Cassandra 2.1, etc.), but I get
a bad feeling about each.
Couldn't find an exact answer to this through searches...
Regards,
Tuukka
P.S. I first asked this at SO before realizing the traffic there is very
low:
http://stackoverflow.com/questions/24380158/storing-a-list-of-mixed-types-in-cassandra
Re: Storing values of mixed types in a list
Jeremy, with blob field (ByteBuffer), I can query exact matches (just
encode the value in query), but greater/less than queries would not work.
Any sort of serialization kills native ways to query data -- Not
necessarily. You still use normal types (uuid, string, timestamp,...) for
clustering columns and use them for querying. For the cells where you store
values, use blob type.
On Tue, Jun 24, 2014 at 8:21 PM, Tuukka Mustonen tuukka.musto...@gmail.com
wrote:
What if I need to query by list items?
1. Jeremy, with blob field (ByteBuffer), I can query exact matches (just
encode the value in query), but greater/less than queries would not work.
Any sort of serialization kills native ways to query data
2. Even with user defined types, I would need to define separate fields
for each value. Running queries would be cumbersome (something like WHERE
items CONTAINS {'text_value': 'foobar'} or WHERE items CONTAINS
{'int_value': 3}. Pavel, did you mean like this?
I'm running 2.1rc1 with python driver 2.0.2.
Tuukka
On Tue, Jun 24, 2014 at 4:39 PM, Pavel Kogan pavel.ko...@cortica.com
wrote:
1) You can use list of strings which are serialized JSONs, or use
ByteBuffer with your own serialization as Jeremy suggested.
2) Use Cassandra 2.1 (not officially released yet) were there is new
feature of user defined types.
Pavel
On Tue, Jun 24, 2014 at 9:18 AM, Jeremy Jongsma jer...@barchart.com
wrote:
Use a ByteBuffer value type with your own serialization (we use protobuf
for complex value structures)
On Jun 24, 2014 5:30 AM, Tuukka Mustonen tuukka.musto...@gmail.com
wrote:
Hello,
I need to store a list of mixed types in Cassandra. The list may
contain numbers, strings and booleans. So I would need something like
list?.
Is this possible in Cassandra and if not, what workaround would you
suggest for storing a list of mixed type items? I sketched a few (using a
list per type, using list of user types in Cassandra 2.1, etc.), but I get
a bad feeling about each.
Couldn't find an exact answer to this through searches...
Regards,
Tuukka
P.S. I first asked this at SO before realizing the traffic there is
very low:
http://stackoverflow.com/questions/24380158/storing-a-list-of-mixed-types-in-cassandra
