Re: is this correct, thrift unportable to CQL3Š.
Thanks Sylvain,
However,we tried missing the value but it didn't work :(
So our code is like below where we are using 3 values if colname is not
null..else 2 values..
if (key != null) {
PreparedStatement statement = session.prepare(INSERT INTO
keys.StringIndice (id, colname, colvalue) VALUES (?, ?, ?));
BoundStatement boundStatement = new
BoundStatement(statement);
session.execute(boundStatement.bind(StandardConverters.convertFromBytes(String.class,
rowKey), key, ByteBuffer.wrap(value)));
} else {
PreparedStatement statement = session.prepare(INSERT INTO
+ keys + . + table + (id, colvalue) VALUES (?, ?));
BoundStatement boundStatement = new
BoundStatement(statement);
session.execute(boundStatement.bind(StandardConverters.convertFromBytes(String.class,
rowKey), ByteBuffer.wrap(value)));
}
And, I did that and getting this exception:
Exception:Missing PRIMARY KEY part colname since colvalue is set
And just FYI. Our Column Family definition is below:
CREATE TABLE keys.StringIndice (id text,
colname text,
colvalue blob,
PRIMARY KEY (id,colname, colvalue)) WITH COMPACT STORAGE)
Thanks again,
Vikas Goyal
On Tue, Sep 24, 2013 at 7:02 PM, Sylvain Lebresne sylv...@datastax.comwrote:
Short answer: not, this is not correct.
Longer answer: what you call null is actually an empty value (which is
*not* the same thing, unless you consider an empty string is the same thing
than a null string). As it happens, C* always an empty value as a valid
value for any type and that's true of both thrift and CQL3. What is true is
that CQL3 discourage the use of empty values for type for which it doesn't
particularly make sense (integers typically) by not having a particular
easy to use syntax to input them. But that's supported nonetheless. If you
use a prepared statement for instance (where you send values already
serialized), nothing will prevent you from sending an empty value. Even if
you don't want to use a prepared statement, CQL3 has conversion functions (
http://cassandra.apache.org/doc/cql3/CQL.html#blobFun) that allows to do
it (for instance, blobAsInt(0x) will be an empty int value).
--
Sylvain
On Tue, Sep 24, 2013 at 2:36 PM, Hiller, Dean dean.hil...@nrel.govwrote:
Many applications in thrift use the wide row with composite column name
and as an example, let's say golf score for instance and we end up with
golf score : pk like so
null : pk56
null : pk45
89 : pk90
89: pk87
90: pk101
95: pk17
Notice that there are some who do not have a golf score(zero would not
quite make sense and would be interpreted as a golf score). I am hearing
from this post if they are correct that this is not portable to CQL3??? Is
this true?
http://stackoverflow.com/questions/18963248/how-can-i-have-null-column-value-for-a-composite-key-column-in-cql3
(This sounds like a major deficit to me as the wide row now can only be
used where actual values exist?). Is it possible to port this pattern
to CQL3?
Thanks,
Dean
Re: is this correct, thrift unportable to CQL3Š.
Ok. Great. It works for String and Decimal/Float but not for integer data
type..
i.e,, if I am passing to the composite key column which is either text
or float, it works..
session.execute(boundStatement.bind(rowkey, , ByteBuffer.wrap(value)));
But not working with bigint, int or varint..and getting following exception;
Exception:Invalid type for value 1 of CQL type varint, expecting class
java.math.BigInteger but class java.lang.String provided
..I am exploring more though..
Thanks a ton,
Vikas Goyal
On Tue, Sep 24, 2013 at 9:05 PM, Sylvain Lebresne sylv...@datastax.comwrote:
However,we tried missing the value but it didn't work :(
Right, because not providing a value is akin to having a null value (in
the CQL3 sense of the term, which is different from what Dean asked about)
and null values are not allowed for primary key columns.
You could however insert an *empty* value if you wanted, which in you case
is just inserting an empty string since colname is a string. Thrift doesn't
allow more or less in that case.
--
Sylvain
So our code is like below where we are using 3 values if colname is not
null..else 2 values..
if (key != null) {
PreparedStatement statement = session.prepare(INSERT
INTO keys.StringIndice (id, colname, colvalue) VALUES (?, ?, ?));
BoundStatement boundStatement = new
BoundStatement(statement);
session.execute(boundStatement.bind(StandardConverters.convertFromBytes(String.class,
rowKey), key, ByteBuffer.wrap(value)));
} else {
PreparedStatement statement = session.prepare(INSERT
INTO + keys + . + table + (id, colvalue) VALUES (?, ?));
BoundStatement boundStatement = new
BoundStatement(statement);
session.execute(boundStatement.bind(StandardConverters.convertFromBytes(String.class,
rowKey), ByteBuffer.wrap(value)));
}
And, I did that and getting this exception:
Exception:Missing PRIMARY KEY part colname since colvalue is set
And just FYI. Our Column Family definition is below:
CREATE TABLE keys.StringIndice (id text,
colname text,
colvalue blob,
PRIMARY KEY (id,colname, colvalue)) WITH COMPACT STORAGE)
Thanks again,
Vikas Goyal
On Tue, Sep 24, 2013 at 7:02 PM, Sylvain Lebresne
sylv...@datastax.comwrote:
Short answer: not, this is not correct.
Longer answer: what you call null is actually an empty value (which is
*not* the same thing, unless you consider an empty string is the same thing
than a null string). As it happens, C* always an empty value as a valid
value for any type and that's true of both thrift and CQL3. What is true is
that CQL3 discourage the use of empty values for type for which it doesn't
particularly make sense (integers typically) by not having a particular
easy to use syntax to input them. But that's supported nonetheless. If you
use a prepared statement for instance (where you send values already
serialized), nothing will prevent you from sending an empty value. Even if
you don't want to use a prepared statement, CQL3 has conversion functions (
http://cassandra.apache.org/doc/cql3/CQL.html#blobFun) that allows to
do it (for instance, blobAsInt(0x) will be an empty int value).
--
Sylvain
On Tue, Sep 24, 2013 at 2:36 PM, Hiller, Dean dean.hil...@nrel.govwrote:
Many applications in thrift use the wide row with composite column name
and as an example, let's say golf score for instance and we end up with
golf score : pk like so
null : pk56
null : pk45
89 : pk90
89: pk87
90: pk101
95: pk17
Notice that there are some who do not have a golf score(zero would not
quite make sense and would be interpreted as a golf score). I am hearing
from this post if they are correct that this is not portable to CQL3??? Is
this true?
http://stackoverflow.com/questions/18963248/how-can-i-have-null-column-value-for-a-composite-key-column-in-cql3
(This sounds like a major deficit to me as the wide row now can only be
used where actual values exist?). Is it possible to port this pattern
to CQL3?
Thanks,
Dean
Does collection in CQL3 have certain limits?
As there are two ways to support wide rows in CQL3..One is to use composite keys and another is to use collections like Map, List and Set. The composite keys method can have millions of columns (transposed to rows).. This is solving some of our use cases. However, if we use collections, I want to know if there is a limit that the collections can store a certain number/amount of data (Like earlier with Thrift C* supports up-to 2 billion columns in a row) Thanks, Vikas Goyal
PlayOrm latest release is available in Maven now
For those who are using playorm for cassandra, latest release (1.4.4) is available in maven repo now. It has following new features: - Support for @NoSqlEmbedable for user defined entities. - In SJQL, Ability to - Delete rows(DELETE), - Delete a single column(DELETECOLUMN), - Query with IN attribute and - Also ORDER BY ..is now added - Astyanax version is upgraded to 1.56.18 - Storage type of *ToOne is changed to composite. - Command line tool now provides support for @NoSqlEmbedded and @NoSqlEmbedable - Added support for DateTime as index and also support for querying the JodaTimes -
