Row iteration over indexed clause

[Vivek Mishra-2]

Hi,

Is it possible to iterate and fetch in chunks using thrift API by querying using "secondary indexes"?

-Vivek

[shimi]

Yes.

use get_indexed_slices (http://wiki.apache.org/cassandra/API)

On Tue, Mar 13, 2012 at 2:12 PM, Vivek Mishra <[hidden email]> wrote:

Hi,

Is it possible to iterate and fetch in chunks using thrift API by querying using "secondary indexes"?

-Vivek

[Vivek Mishra-2]

Thanks.

Attribute	Type	Default	Required	Description
expressions	list<IndexExpression>	n/a	Y	The list of IndexExpression objects which must contain one EQ IndexOperator among the expressions
start_key	binary	n/a	Y	Start the index query at the specified key - can be set to '', i.e., an empty byte array, to start with the first key
count	integer	100	Y	The number of results to which the index query will be constrained

How do i iterate using it? How do i ensure that it should not return me previous results(without i need to keep something in-memory)?

This is the method i am looking into:

get_indexed_slices(ColumnParent column_parent, IndexClause index_clause, SlicePredicate column_predicate, ConsistencyLevel consistency_level)

It does not have anything like count.

Thanks,

Vivek

On Tue, Mar 13, 2012 at 6:24 PM, Shimi Kiviti <[hidden email]> wrote:

Yes.

use get_indexed_slices (http://wiki.apache.org/cassandra/API)

On Tue, Mar 13, 2012 at 2:12 PM, Vivek Mishra <[hidden email]> wrote:

Hi,

Is it possible to iterate and fetch in chunks using thrift API by querying using "secondary indexes"?

-Vivek

[aaron morton]

If you want 100 results per call, ask for 101. Use the first 100, when you get to the 101'st do not examine it's data. Instead use it's key as the start to get the next 101.

Cheers

-----------------

Aaron Morton

Freelance Developer

@aaronmorton

http://www.thelastpickle.com

On 14/03/2012, at 2:03 AM, Vivek Mishra wrote:

Thanks.

Attribute	Type	Default	Required	Description
expressions	list<IndexExpression>	n/a	Y	The list of IndexExpression objects which must contain one EQ IndexOperator among the expressions
start_key	binary	n/a	Y	Start the index query at the specified key - can be set to '', i.e., an empty byte array, to start with the first key
count	integer	100	Y	The number of results to which the index query will be constrained

How do i iterate using it? How do i ensure that it should not return me previous results(without i need to keep something in-memory)?

This is the method i am looking into:

get_indexed_slices(ColumnParent column_parent, IndexClause index_clause, SlicePredicate column_predicate, ConsistencyLevel consistency_level)

It does not have anything like count.

Thanks,

Vivek

On Tue, Mar 13, 2012 at 6:24 PM, Shimi Kiviti <[hidden email]> wrote:

Yes.

use get_indexed_slices (http://wiki.apache.org/cassandra/API)

On Tue, Mar 13, 2012 at 2:12 PM, Vivek Mishra <[hidden email]> wrote:

Hi,

Is it possible to iterate and fetch in chunks using thrift API by querying using "secondary indexes"?

-Vivek

[Tyler Hobbs-2]

Are you writing a new client for a language that doesn't have good drivers?  If not, most of the existing clients already break up the query into chunks, I think.

The pycassa implementation of this might be a useful reference: https://github.com/pycassa/pycassa/blob/master/pycassa/columnfamily.py#L561

On Wed, Mar 14, 2012 at 2:35 AM, aaron morton <[hidden email]> wrote:

If you want 100 results per call, ask for 101. Use the first 100, when you get to the 101'st do not examine it's data. Instead use it's key as the start to get the next 101.

Cheers

-----------------

Aaron Morton

Freelance Developer

@aaronmorton

http://www.thelastpickle.com

On 14/03/2012, at 2:03 AM, Vivek Mishra wrote:

Thanks.

Attribute	Type	Default	Required	Description
expressions	list<IndexExpression>	n/a	Y	The list of IndexExpression objects which must contain one EQ IndexOperator among the expressions
start_key	binary	n/a	Y	Start the index query at the specified key - can be set to '', i.e., an empty byte array, to start with the first key
count	integer	100	Y	The number of results to which the index query will be constrained

How do i iterate using it? How do i ensure that it should not return me previous results(without i need to keep something in-memory)?

This is the method i am looking into:

get_indexed_slices(ColumnParent column_parent, IndexClause index_clause, SlicePredicate column_predicate, ConsistencyLevel consistency_level)

It does not have anything like count.

Thanks,

Vivek

On Tue, Mar 13, 2012 at 6:24 PM, Shimi Kiviti <[hidden email]> wrote:

Yes.

use get_indexed_slices (http://wiki.apache.org/cassandra/API)

On Tue, Mar 13, 2012 at 2:12 PM, Vivek Mishra <[hidden email]> wrote:

Hi,

Is it possible to iterate and fetch in chunks using thrift API by querying using "secondary indexes"?

-Vivek

--
Tyler Hobbs
DataStax