Note that LZ4 compression is used by default. If you want to disable
compression you can do this:CREATE/ALTER TABLE ... WITH compression = {
'sstable_compression' : '' };
Best,
Romain
Le Vendredi 9 septembre 2016 8h12, Alexandr Porunov
<alexandr.poru...@gmail.com> a écrit :
Hello Romain,
Thank you very much for the explanation!
I have just run a simple test to compare both situations.I have run two VM
equivalent machines.Machine 1:CREATE KEYSPACE "test" WITH REPLICATION = {
'class' : 'SimpleStrategy', 'replication_factor' : 1 };
CREATE TABLE test.simple ( id bigint PRIMARY KEY);
Machine 2:CREATE KEYSPACE "test" WITH REPLICATION = { 'class' :
'SimpleStrategy', 'replication_factor' : 1 };
CREATE TABLE test.simple ( id blob PRIMARY KEY);
And have put 13421772 primary keys from 1 to 13421772 in both machines.
Results:Machine 1: size of the data folder: 495864 bytesMachine 2: size of the
data folder: 495004 bytes
So here is almost no any difference between them (even happened with blob
storage cost 1 MB less).
I am happy about it because I need to store special encoded primary keys with
80 bits each. So I can use blob as a primary key without hesitation.
Best regards,Alexandr
On Fri, Sep 9, 2016 at 1:20 AM, Romain Hardouin <romainh...@yahoo.fr> wrote:
Hi,
Disk-wise it's the same because a bigint is serialized as a 8 bytes ByteBuffer
and if you want to store a Long as bytes into a blob type it will take 8 bytes
too, right?The difference is the validation. The blob ByteBuffer will be stored
as is whereas the bigint will be validated. So technically the Long is slower,
but I guess that's not noticeable.
Yes you can use a blob as a partition key. I would use the bigint both for
validation and clarity.
Best,
Romain
Le Mercredi 7 septembre 2016 22h54, Alexandr Porunov
<alexandr.poru...@gmail.com> a écrit :
Hello,
I need to store a "Long" Java variable.The question is: whether the storage
cost is the same both for store hex representation of "Long" variable to the
blob and for store "Long" variable to the bigint?Are there any performance pros
or cons?Is it OK to use blob as primary key?
Sincerely,Alexandr
