bq. Using a scan for just one known row Can you batch some deletions in one invocation of the endpoint ?
Supporting filter in the delete path requires non-trivial amount of work. So for the time being, please use BulkDeleteEndpoint. Cheers On Wed, Dec 24, 2014 at 6:23 PM, Devaraja Swami <devarajasw...@gmail.com> wrote: > Thanks for your reply, Ted. I looked into the coprocessor example you > provided. It will definitely address my specific need. However, two aspects > of this approach seem less than ideal to me: > 1. Being a coprocessor service, I believe the endpoint needs to be > pre-installed on the region servers. This is not possible in typical cases > where the user does not have influence over the HBase installation or > administrators. > 2. In my use case, I already know the row key for which I need the > specified column qualifier prefixes to be deleted. Using a scan for just > one known row, as in the coprocessor example, appears to be a bit of an > overkill... > > Overall, the coprocessor approach seems somewhat like using a hammer to > push in a pushpin. Specifying a filter from the client side is much easier > and more straightforward, IMHO. > > > On Wed, Dec 24, 2014 at 2:01 PM, Ted Yu <yuzhih...@gmail.com> wrote: > > > Have you looked > > at > > > hbase-examples/src/main/java/org/apache/hadoop/hbase/coprocessor/example/BulkDeleteEndpoint.java > > to see if it fits your need ? > > > > Cheers > > > > On Wed, Dec 24, 2014 at 1:34 PM, Devaraja Swami <devarajasw...@gmail.com > > > > wrote: > > > > > Are there any plans for including a Filter for Delete? > > > Currently, the only way seems to be via checkAndDelete in HTable/Table. > > > This is helpful but does not cover all use cases. > > > > > > For e.g., I use column qualifier prefixes as a sort of poor man's 2rd > > level > > > of indexing (i.e, 3 levels of indexing comprising row key --> column > > > qualifier prefix --> column qualifier suffix). This works well for Get > > and > > > Scan, since I can use a prefix column qualifier filter for the 2nd > > indexing > > > level. > > > However, I am not able to specify that an entire set of column > qualifiers > > > sharing the same prefix should be deleted, without doing a Get first to > > > identify all the full column qualifier values with the same prefix, and > > > then adding those qualifiers to the Delete. This is obviously highly > > > inefficient. > > > > > > checkAndDelete doesn't help here since it does not support prefix > tests. > > > Moreover, I cannot just add a new column family for every unique column > > > qualifier prefix I need in my data model. In general, using just one > > column > > > family per table seems to be most efficient. > > > > > > I can think of other use cases where one would need to delete a lot of > > > columns that match one of the available HBase filters, but whose exact > > > column qualifier values are not known at deletion time at the client. > > > > > > All these uses cases can be taken care of by allowing Delete to > support a > > > setFilter method, exactly as in the case of Get and Scan. > > > > > >
