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From Ryan Rawson <ryano...@gmail.com>
Subject Re: retrieving timestamp from Result
Date Mon, 15 Nov 2010 23:50:12 GMT
Within a "Result" object you are only going to get columns for a
single row.  So the 2 byte[] are family and qualifier.  Check the
javadoc.  I wrote quite a bit of documentation on these APIs.

Thanks,
-ryan

On Mon, Nov 15, 2010 at 3:42 PM, Ted Yu <yuzhihong@gmail.com> wrote:
> Since there may be more than one qualifier for a column family, is it
> reasonable to add Result.getColumnLatest(byte[]) which returns the latest
> column for given family ?
>
> Thanks
>
> On Mon, Nov 15, 2010 at 2:12 PM, Ryan Rawson <ryanobjc@gmail.com> wrote:
>
>> The javadoc details what to expect.
>>
>> You can also call Result.getColumnLatest(byte[],byte[])
>>
>> The resulting KeyValue has methods like getTimestamp() etc.
>>
>> -ryan
>>
>>
>> On Mon, Nov 15, 2010 at 2:02 PM, Ted Yu <yuzhihong@gmail.com> wrote:
>> > We used the following code to see if the "Cell" (pardon me for using the
>> old
>> > term) returned from scanner was of certain timestamp:
>> >            if (result.getCellValue().getTimestamp() == ts){
>> >
>> > In 0.90, I don't see method which returns the timestamp for Result.
>> > I am wondering if the above check can be omitted since we specify the
>> > following for the Scan:
>> >        scan.setTimeStamp(ts);
>> > If not, please advise the correct way of retrieving timestamp from
>> Result.
>> >
>> > If I call Result.raw() and get two KeyValue's, which should be the
>> KeyValue
>> > whose timestamp conforms to the semantics of our check shown at the top ?
>> >
>> > Thanks
>> >
>> > On Mon, Nov 15, 2010 at 12:38 PM, Ryan Rawson <ryanobjc@gmail.com>
>> wrote:
>> >
>> >> That is correct, those classes were deprecated in 0.20, and now gone in
>> >> 0.90.
>> >>
>> >> Now you will want to use HTable and Result.
>> >>
>> >> Also Filter.getNextKeyHint() is an implementation detail, have a look
>> >> at the other filters to get a sense of what it does.
>> >>
>> >> On Mon, Nov 15, 2010 at 12:33 PM, Ted Yu <yuzhihong@gmail.com> wrote:
>> >> > Just a few findings when I tried to compile our 0.20.6 based code with
>> >> this
>> >> > new release:
>> >> >
>> >> > HConstants is final class now instead of interface
>> >> > RowFilterInterface is gone
>> >> > org.apache.hadoop.hbase.io.Cell is gone
>> >> > org.apache.hadoop.hbase.io.RowResult is gone
>> >> > constructor
>> >> >
>> >>
>> HColumnDescriptor(byte[],int,java.lang.String,boolean,boolean,int,boolean)
>> >> > is gone
>> >> > Put.setTimeStamp() is gone
>> >> > org.apache.hadoop.hbase.filter.Filter has added
>> >> > getNextKeyHint(org.apache.hadoop.hbase.KeyValue)
>> >> >
>> >> > If you know the alternative to some of the old classes, please share.
>> >> >
>> >> > On Mon, Nov 15, 2010 at 2:51 AM, Stack <stack@duboce.net> wrote:
>> >> >
>> >> >> The first hbase 0.90.0 release candidate is available for download:
>> >> >>
>> >> >>  http://people.apache.org/~stack/hbase-0.90.0-candidate-0/<http://people.apache.org/%7Estack/hbase-0.90.0-candidate-0/>
>> <http://people.apache.org/%7Estack/hbase-0.90.0-candidate-0/>
>> >> <http://people.apache.org/%7Estack/hbase-0.90.0-candidate-0/>
>> >> >>
>> >> >> HBase 0.90.0 is the major HBase release that follows 0.20.0 and
the
>> >> >> fruit of the 0.89.x development release series we've been running
of
>> >> >> late.
>> >> >>
>> >> >> More than 920 issues have been closed since 0.20.0.  Release notes
>> are
>> >> >> available here: http://su.pr/8LbgvK.
>> >> >>
>> >> >> HBase 0.90.0 runs on Hadoop 0.20.x.  It does not currently run
on
>> >> >> Hadoop 0.21.0.   HBase will lose data unless it is running on
an
>> >> >> Hadoop HDFS 0.20.x that has a durable sync. Currently only the
>> >> >> branch-0.20-append branch [1] has this attribute. No official
>> releases
>> >> >> have been made from this branch as yet so you will have to build
your
>> >> >> own Hadoop from the tip of this branch or install Cloudera's CDH3
[2]
>> >> >> (Its currently in beta).  CDH3b2 or CDHb3 have the 0.20-append
>> patches
>> >> >> needed to add a durable sync. See CHANGES.txt [3] in
>> >> >> branch-0.20-append to see list of patches involved.
>> >> >>
>> >> >> There is no migration necessary.  Your data written with HBase
0.20.x
>> >> >> (or with HBase 0.89.x) is readable by HBase 0.90.0.  A shutdown
and
>> >> >> restart after putting in place the new HBase should be all thats
>> >> >> involved.  That said, once done, there is no going back to 0.20.x
>> once
>> >> >> the transition has been made.   HBase 0.90.0 and HBase 0.89.x
write
>> >> >> region names differently in the filesystem.  Rolling restart from
>> >> >> 0.20.x or 0.89.x to 0.90.0RC0 will not work.
>> >> >>
>> >> >> Should we release this candidate as hbase 0.90.0?  Take it for
a
>> spin.
>> >> >>  Check out the doc.  Vote +1/-1 by November 22nd.
>> >> >>
>> >> >> Yours,
>> >> >> The HBasistas
>> >> >> P.S. For why the version 0.90 and whats new in HBase 0.90, see
slides
>> >> >> 4-10 in this deck [4]
>> >> >>
>> >> >> 1.
>> >> http://svn.apache.org/viewvc/hadoop/common/branches/branch-0.20-append
>> >> >> 2. http://archive.cloudera.com/docs/
>> >> >> 3.
>> >> >>
>> >>
>> http://svn.apache.org/viewvc/hadoop/common/branches/branch-0.20-append/CHANGES.txt
>> >> >> 4. http://hbaseblog.com/2010/07/04/hug11-hbase-0-90-preview-wrap-up/
>> >> >>
>> >> >
>> >>
>> >
>>
>

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