Re: Composite column names: How much space do they occupy ?
What is the definition of the composite type and what is CS.toByteBuffer ? CompositeTypes have a small overhead see https://github.com/apache/cassandra/blob/trunk/src/java/org/apache/cassandra/db/marshal/CompositeType.java Hope that helps. Aaron - Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 2/01/2012, at 6:25 PM, Ertio Lew wrote: I am storing composite column names which are made up of two integer components. However I am shocked after seeing the storage overhead of these. I just tried out a composite name (with single integer component): Composite composite = new Composite(); composite.addComponent(-165376575,is); System.out.println(CS.toByteBuffer( composite ).array().length); // the result is 256 After writing then reading back this composite column from cassandra: System.out.println(CS.toByteBuffer( readColumn.getName() ).array().length); // the result is 91 How much is the storage overhead, as I am quite sure that I'm making a mistake in realizing the actual values ?
Re: Composite column names: How much space do they occupy ?
Sorry I forgot to tell that I'm using Hector to communicate with Cassandra. CS.toByteBuffer is to convert the composite type name to ByteBuffer. Can anyone aware of Hector API enlighten me why am I seeing this size for the composite type names. On Mon, Jan 2, 2012 at 2:52 PM, aaron morton aa...@thelastpickle.comwrote: What is the definition of the composite type and what is CS.toByteBuffer ? CompositeTypes have a small overhead see https://github.com/apache/cassandra/blob/trunk/src/java/org/apache/cassandra/db/marshal/CompositeType.java Hope that helps. Aaron - Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 2/01/2012, at 6:25 PM, Ertio Lew wrote: I am storing composite column names which are made up of two integer components. However I am shocked after seeing the storage overhead of these. I just tried out a composite name (with single integer component): Composite composite = new Composite(); composite.addComponent(-165376575,is); System.out.println(CS.toByteBuffer( composite ).array().length); // the result is 256 After writing then reading back this composite column from cassandra: System.out.println(CS.toByteBuffer( readColumn.getName() ).array().length); // the result is 91 How much is the storage overhead, as I am quite sure that I'm making a mistake in realizing the actual values ?
Re: Composite column names: How much space do they occupy ?
I am not familiar enough with Hector to tell you if it is doing something special here, but note that: 1) you may have better luck getting that kind of question answered quickly by using the Hector mailing list. 2) that may or may not change what you're seeing (since again I don't know what Hector is actually doing), but bb.array().length is not a reliable way to get the effective length of a ByteBuffer, as it is perfectly legit to have a byte buffer only use parts of it's underlying array. You should use the remaining() method instead. -- Sylvain On Mon, Jan 2, 2012 at 12:29 PM, Ertio Lew ertio...@gmail.com wrote: Sorry I forgot to tell that I'm using Hector to communicate with Cassandra. CS.toByteBuffer is to convert the composite type name to ByteBuffer. Can anyone aware of Hector API enlighten me why am I seeing this size for the composite type names. On Mon, Jan 2, 2012 at 2:52 PM, aaron morton aa...@thelastpickle.com wrote: What is the definition of the composite type and what is CS.toByteBuffer ? CompositeTypes have a small overhead see https://github.com/apache/cassandra/blob/trunk/src/java/org/apache/cassandra/db/marshal/CompositeType.java Hope that helps. Aaron - Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 2/01/2012, at 6:25 PM, Ertio Lew wrote: I am storing composite column names which are made up of two integer components. However I am shocked after seeing the storage overhead of these. I just tried out a composite name (with single integer component): Composite composite = new Composite(); composite.addComponent(-165376575,is); System.out.println(CS.toByteBuffer( composite ).array().length); // the result is 256 After writing then reading back this composite column from cassandra: System.out.println(CS.toByteBuffer( readColumn.getName() ).array().length); // the result is 91 How much is the storage overhead, as I am quite sure that I'm making a mistake in realizing the actual values ?
Re: Composite column names: How much space do they occupy ?
Yes that makes a lot of sense! on using remaining() method I see the proper expected sizes. On Mon, Jan 2, 2012 at 5:26 PM, Sylvain Lebresne sylv...@datastax.comwrote: I am not familiar enough with Hector to tell you if it is doing something special here, but note that: 1) you may have better luck getting that kind of question answered quickly by using the Hector mailing list. 2) that may or may not change what you're seeing (since again I don't know what Hector is actually doing), but bb.array().length is not a reliable way to get the effective length of a ByteBuffer, as it is perfectly legit to have a byte buffer only use parts of it's underlying array. You should use the remaining() method instead. -- Sylvain On Mon, Jan 2, 2012 at 12:29 PM, Ertio Lew ertio...@gmail.com wrote: Sorry I forgot to tell that I'm using Hector to communicate with Cassandra. CS.toByteBuffer is to convert the composite type name to ByteBuffer. Can anyone aware of Hector API enlighten me why am I seeing this size for the composite type names. On Mon, Jan 2, 2012 at 2:52 PM, aaron morton aa...@thelastpickle.com wrote: What is the definition of the composite type and what is CS.toByteBuffer ? CompositeTypes have a small overhead see https://github.com/apache/cassandra/blob/trunk/src/java/org/apache/cassandra/db/marshal/CompositeType.java Hope that helps. Aaron - Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 2/01/2012, at 6:25 PM, Ertio Lew wrote: I am storing composite column names which are made up of two integer components. However I am shocked after seeing the storage overhead of these. I just tried out a composite name (with single integer component): Composite composite = new Composite(); composite.addComponent(-165376575,is); System.out.println(CS.toByteBuffer( composite ).array().length); // the result is 256 After writing then reading back this composite column from cassandra: System.out.println(CS.toByteBuffer( readColumn.getName() ).array().length); // the result is 91 How much is the storage overhead, as I am quite sure that I'm making a mistake in realizing the actual values ?
Composite column names: How much space do they occupy ?
I am storing composite column names which are made up of two integer components. However I am shocked after seeing the storage overhead of these. I just tried out a composite name (with single integer component): Composite composite = new Composite(); composite.addComponent(-165376575,is); System.out.println(CS.toByteBuffer( composite ).array().length); // the result is 256 After writing then reading back this composite column from cassandra: System.out.println(CS.toByteBuffer( readColumn.getName() ).array().length); // the result is 91 How much is the storage overhead, as I am quite sure that I'm making a mistake in realizing the actual values ?
