tag:blogger.com,1999:blog-7235509382075756737.post7087538800814510902..comments2024-03-15T22:53:02.707-07:00Comments on HBase: HBase intra row scanningLars Hofhanslhttp://www.blogger.com/profile/17852987569207015300noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-7235509382075756737.post-43003380172813519022012-12-20T12:06:38.866-08:002012-12-20T12:06:38.866-08:00Hi Shengjie,
ColumnRangeFilter does work without ...Hi Shengjie,<br /><br />ColumnRangeFilter does work without selected in the Scan object.<br />The point here, though, to avoid scans over many KeyValue (columns). Imagine a single row with 1 million columns. Without ColumnRangeFilter or ColumnPrefixFilter you would have to retrieve all column even if you only care about a subset of them.<br /><br />Similarly, if you use a ColumnRangeFilter without limiting the row keys HBase will scan over all rows in the table. Within these rows it will efficiently only return the columns you are interested in. So it depends on what you want to achieve.<br />Lars Hofhanslhttps://www.blogger.com/profile/17852987569207015300noreply@blogger.comtag:blogger.com,1999:blog-7235509382075756737.post-55305554941227816772012-12-20T02:43:33.296-08:002012-12-20T02:43:33.296-08:00Hi Lars,
Great post, it really changes the way I ...Hi Lars,<br /><br />Great post, it really changes the way I think when it comes to schema design. quick question - does ColumnRangeFilter work without a rowkey. eg. I want query all the columns starting with "abc" and ending with "abd" for all the rows. if it does, I think the efficiency will be just like scan rowkey, right?Shengjie Minhttps://www.blogger.com/profile/10599355579462177336noreply@blogger.comtag:blogger.com,1999:blog-7235509382075756737.post-58945406182719284142012-01-24T08:18:49.745-08:002012-01-24T08:18:49.745-08:00@Kisalay: The column qualifiers are sorted within ...@Kisalay: The column qualifiers are sorted within their row (and column family). That is why the ColumnRangeFilter can seek ahead efficiently.<br /><br />@Bruno: Thanks. I am glad you find it useful. More to come.Lars Hofhanslhttps://www.blogger.com/profile/17852987569207015300noreply@blogger.comtag:blogger.com,1999:blog-7235509382075756737.post-69945369632742781292012-01-24T05:06:22.341-08:002012-01-24T05:06:22.341-08:00Just discovered your blog: great stuff!Just discovered your blog: great stuff!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-7235509382075756737.post-42423758636520710792012-01-24T03:15:03.150-08:002012-01-24T03:15:03.150-08:00Hi Lars,
Thanks for the gr8 post. I had a doubt: ...Hi Lars,<br /><br />Thanks for the gr8 post. I had a doubt: Does HBase store the cells indexed by the column-qualifiers or is it a list ? If it is a list then will Column-Range-Filter and Column-Prefix-Filter result into a scan of all the qualifiers in that column-family for that row-key ?<br /><br />Thanks<br />KisalayKisalayhttps://www.blogger.com/profile/02548255331438754635noreply@blogger.com