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? >>>> version=12334393&projectId=12315120 >>>> <https://issues.apache.org/jira/secure/ReleaseNote.jspa? >>>> version=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 >>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>>
