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From Ted Yu <yuzhih...@gmail.com>
Subject Re: retrieving timestamp from Result
Date Mon, 15 Nov 2010 23:42:49 GMT
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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