The phoenix cursors implementation is designed to work well for our deep paging use-cases. https://github.com/apache/phoenix/pull/229
the cursor on the client will keep track of offset to jump on the next page fetch. Although Aggregate queries will not leverage this feature. -Ani On Wed, May 24, 2017 at 3:36 AM, Ciureanu Constantin < ciureanu.constan...@gmail.com> wrote: > Of course not in HBase, but the server is Phoenix so there's where the VLH > could be implemented like this: > - run the query on top of HBase (as normal) > - "cache" first N result rows (eg. 1M maxim) = serialize the results on > disk (eg. using temp folder, in some pre-processed "pages" structure) > - return page 1 > - any subsequent request from the client should contain a flag that it's > not the first page request > - <wait for the client to ask for page X of the results> and return the > page X rows > - wait for a number of N minutes (configurable) -> discard the results > from disk (or any N minutes have a cleanup task to delete older cached > results) > > > > > 2017-05-18 22:02 GMT+02:00 James Taylor <jamestay...@apache.org>: > >> HBase does not lend itself to that pattern. Rows overlap in HFiles (by >> design). There's no facility to jump to the Nth row. Best to use the RVC >> mechanism. >> >> On Thu, May 18, 2017 at 12:03 PM Ciureanu Constantin < >> ciureanu.constan...@gmail.com> wrote: >> >>> What about using the VLH pattern? >>> An d keep the offsets for each page in the server side, for a while... >>> (the client might not need all of them, might also never ask for next page) >>> >>> http://www.oracle.com/technetwork/java/valuelisthandler-142464.html >>> >>> On May 18, 2017 20:02, "James Taylor" <jamestay...@apache.org> wrote: >>> >>>> Yes, it's expected that query performance would degrade as the offset >>>> increases. The best Phoenix can do for OFFSET is to scan the rows and count >>>> them until the offset is reached. Use the row value constructor technique >>>> instead to prevent this: https://phoenix.apache.org/paged.html >>>> >>>> On Thu, May 18, 2017 at 6:18 AM, Sumanta Gh <sumanta...@tcs.com> wrote: >>>> >>>>> Thanks Rafa. >>>>> This is working perfectly fine with 4.10. >>>>> Are the offset and limit enforced on client side? I find the >>>>> performance of query gradually degrades as I increase the offset value. >>>>> >>>>> >>>>> Regards >>>>> Sumanta >>>>> >>>>> >>>>> -----rafa <raf...@gmail.com> wrote: ----- >>>>> To: user@phoenix.apache.org >>>>> From: rafa <raf...@gmail.com> >>>>> Date: 05/18/2017 06:15PM >>>>> Subject: Re: pagination >>>>> >>>>> >>>>> Hi Sumanta, >>>>> >>>>> It is supported from 4.8: >>>>> >>>>> Apache Phoenix enables OLTP and operational analytics for Hadoop >>>>> through >>>>> SQL support and integration with other projects in the ecosystem such >>>>> as >>>>> Spark, HBase, Pig, Flume, MapReduce and Hive. >>>>> >>>>> We're pleased to announce our 4.8.0 release which includes: >>>>> - Local Index improvements[1] >>>>> - Integration with hive[2] >>>>> - Namespace mapping support[3] >>>>> - VIEW enhancements[4] >>>>> - Offset support for paged queries[5] >>>>> - 130+ Bugs resolved[6] >>>>> - HBase v1.2 is also supported ( with continued support for v1.1, v1.0 >>>>> & >>>>> v0.98) >>>>> - Many performance enhancements(related to StatsCache, distinct, Serial >>>>> query with Stats etc)[6] >>>>> >>>>> The release is available in source or binary form here [7]. >>>>> >>>>> Release artifacts are signed with the following key: >>>>> *https://people.apache.org/keys/committer/ankit.asc >>>>> <https://people.apache.org/keys/committer/ankit.asc>* >>>>> >>>>> Thanks, >>>>> The Apache Phoenix Team >>>>> >>>>> [1] https://issues.apache.org/jira/browse/PHOENIX-1734 >>>>> [2] https://issues.apache.org/jira/browse/PHOENIX-2743 >>>>> [3] https://issues.apache.org/jira/browse/PHOENIX-1311 >>>>> [4] https://issues.apache.org/jira/browse/PHOENIX-1508 >>>>> [5] https://issues.apache.org/jira/browse/PHOENIX-2722 >>>>> [6] *https://issues.apache.org/jira/secure/ReleaseNote.jspa?vers >>>>> ion=12334393&projectId=12315120 >>>>> <https://issues.apache.org/jira/secure/ReleaseNote.jspa?vers >>>>> ion=12334393&projectId=12315120>* >>>>> [7] https://phoenix.apache.org/download.html >>>>> >>>>> Regards, >>>>> rafa >>>>> >>>>> >>>>> On Thu, May 18, 2017 at 2:04 PM, rafa <raf...@gmail.com> wrote: >>>>> >>>>>> Ups...sorry my mistake. The Jira is for limit - offset with orderby. >>>>>> sorry. >>>>>> >>>>>> On Thu, May 18, 2017 at 2:02 PM, rafa <raf...@gmail.com> wrote: >>>>>> >>>>>>> Hi Sumanta, >>>>>>> >>>>>>> I think it is not supported yet: >>>>>>> >>>>>>> https://issues.apache.org/jira/browse/PHOENIX-3353 >>>>>>> >>>>>>> Best regards, >>>>>>> rafa >>>>>>> >>>>>>> On Thu, May 18, 2017 at 1:52 PM, Sumanta Gh <sumanta...@tcs.com> >>>>>>> wrote: >>>>>>> >>>>>>>> Hi, >>>>>>>> From which version of Phoenix LIMIT-OFFSET based pagination is >>>>>>>> supported? I am using 4.7, but not able to use OFFSET. >>>>>>>> >>>>>>>> Regards >>>>>>>> Sumanta >>>>>>>> >>>>>>>> =====-----=====-----===== >>>>>>>> Notice: The information contained in this e-mail >>>>>>>> message and/or attachments to it may contain >>>>>>>> confidential or privileged information. If you are >>>>>>>> not the intended recipient, any dissemination, use, >>>>>>>> review, distribution, printing or copying of the >>>>>>>> information contained in this e-mail message >>>>>>>> and/or attachments to it are strictly prohibited. If >>>>>>>> you have received this communication in error, >>>>>>>> please notify us by reply e-mail or telephone and >>>>>>>> immediately and permanently delete the message >>>>>>>> and any attachments. Thank you >>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>> >>>> > -- Anirudha P. Jadhav
