I tried "help update column family".
It gave me :

valid attributes are:
    - column_type: Super or Standard
    - comment: Human-readable column family description. Any string is acceptable
    - rows_cached: Number or percentage of rows to cache
    - row_cache_save_period: Period with which to persist the row cache, in seconds
    - keys_cached: Number or percentage of keys to cache
    - key_cache_save_period: Period with which to persist the key cache, in seconds
    - read_repair_chance: Probability (0.0-1.0) with which to perform read repairs on CL.ONE reads
    - gc_grace: Discard tombstones after this many seconds
    - column_metadata: null
    - memtable_operations: Flush memtables after this many operations
    - memtable_throughput: ... or after this many bytes have been written
    - memtable_flush_after: ... or after this many seconds
    - default_validation_class: null
    - min_compaction_threshold: Avoid minor compactions of less than this number of sstable files
    - max_compaction_threshold: Compact no more than this number of sstable files at once
    - column_metadata: Metadata which describes columns of column family.
        Supported format is [{ k:v, k:v, ... }, { ... }, ...]
        Valid attributes: column_name, validation_class (see comparator),
                          index_type (integer), index_name.

So what is to be used ?
And also if possible please provide information on how do that in Java using Hector.
Thank you.

Vedarth Kulkarni,
TYBSc (Computer Science).

On Thu, Feb 3, 2011 at 2:58 AM, Jonathan Ellis <jbellis@gmail.com> wrote:
On Wed, Feb 2, 2011 at 12:48 PM, Vedarth Kulkarni <vedarthk@gmail.com> wrote:
> Hello there,
> I am using Cassandra 0.7. Is there any way to change the 'compare_with' from
> my program ?, I am using Hector and I am programming in Java.


> Is it possible to change it from the bin/cassandra-cli ?

Yes.  "help update column family;"

Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of DataStax, the source for professional Cassandra support