Shouldn't be an issue since it will always be used for the current
timestamp. Thanks
On 8/20/11 8:06 AM, Mohamed Ibrahim wrote:
That's right if you're using *unsigned* integers. If your integers are
signed (can be negative), then keep the leftmost bit (the highest
significant bit) zero.
Mohamed
On Sat, Aug 20, 2011 at 10:56 AM, Mark<[email protected]> wrote:
Thanks all but I'm actually using ruby as my client so there is no
Long.MAX_VALUE.
Apparently there is an alternative method...
"These composite row keys are similar to what RDBMSs offer, yet you can
control the sort order for each field separately. You could do, for example,
*a bitwise inversion of the date expressed as a long value (the Linux
epoch)*. This would then sort the rows descending by date"
I just want to be clear on the above statement. A bitwise inversion is
simply flipping the bits correct? So if the current time represented as bits
is
100111001001111110010101100111**0
Then the bitwise inversion is
011000110110000001101010000011**0
Is this correct?
On 8/20/11 7:10 AM, [email protected] wrote:
I use this bit from the link sent by Sonal:
reverse_order_stamp is an 8 byte, big endian long with a value of
(Long.MAX_VALUE - epoch). This is so the most recent stamp is at the top
rather than the bottom.
I use (Long.MAX_VALUE - System.getCurrentTimeMillis())**.
-Steve
-----Original Message-----
From: Mark [mailto:static.void.dev@gmail.**com<[email protected]>
]
Sent: Saturday, August 20, 2011 6:29 AM
To: [email protected]
Subject: Re: Reverse timestamp
Thanks but I was more referring to reverse ordered timestamps for
composite keys to be used for sorting purposes.
On 8/19/11 10:26 PM, lars hofhansl wrote:
HBase maps (row-key, column family name, column, timestamp) to a value.
The KeyValues are also sorted by the same attributes in reverse timestamp
order.
The default timestamp is the current time, but you can set any long value
(which does not need correlate in any way to the time domain)
as the time stamp and hence define your own ordering within multiple
version of the same row key.
See Put: Put(byte[] row, long ts).
Is that what you meant?
-- Lars
______________________________**__
From: Mark<[email protected]**>
To: [email protected]
Sent: Friday, August 19, 2011 6:39 PM
Subject: Reverse timestamp
I understand the need but I don't understand how to generate a reverse
timestamp. Can someone please explain how this is accomplished and how I can
test that its working correctly?
Thanks
