Sorry for not being clear enough.
Maybe i misunderstand your suggestion, but what I've done in implement my own
filter, wrapping a FilterList
public class NotFilterList extends Filter {
private FilterList filter;
public NotFilterList(final List<Filter> rowFilters) {
this.filter = new FilterList(rowFilters);
}
public void reset() throws IOException {
this.filter.reset();
}
public boolean filterRowKey(byte[] rowKey, int offset, int length) throws
IOException {
return this.filter.filterRowKey(rowKey, offset, length);
}
public boolean filterAllRemaining() throws IOException {
return this.filter.filterAllRemaining();
}
public ReturnCode filterKeyValue(Cell v) throws IOException {
ReturnCode code = this.filter.filterKeyValue(v);
if (code == ReturnCode.INCLUDE)
code = ReturnCode.SKIP;
else if (code == ReturnCode.INCLUDE_AND_NEXT_COL)
code = ReturnCode.NEXT_COL;
else if (code == ReturnCode.NEXT_ROW)
code = ReturnCode.INCLUDE_AND_NEXT_COL;
else if (code == ReturnCode.SKIP) {
code = ReturnCode.INCLUDE;
}
return code;
}
public Cell transformCell(Cell v) throws IOException {
return this.filter.transformCell(v);
}
public KeyValue transform(KeyValue currentKV) throws IOException {
return this.filter.transform(currentKV);
}
public void filterRowCells(List<Cell> kvs) throws IOException {
this.filter.filterRowCells(kvs);
}
public boolean hasFilterRow() {
return this.filter.hasFilterRow();
}
public boolean filterRow() throws IOException {
return this.filter.filterRow();
}
public KeyValue getNextKeyHint(KeyValue currentKV) throws IOException {
return this.filter.getNextKeyHint(currentKV);
}
public Cell getNextCellHint(Cell currentKV) throws IOException {
return this.filter.getNextCellHint(currentKV);
}
public boolean isFamilyEssential(byte[] name) throws IOException {
return this.filter.isFamilyEssential(name);
}
public byte[] toByteArray() throws IOException {
return this.filter.toByteArray();
}
public static NotFilterList parseFrom(final byte [] pbBytes) throws
DeserializationException {
FilterList filterList = FilterList.parseFrom(pbBytes);
return new NotFilterList(filterList.getFilters());
}
boolean areSerializedFieldsEqual(Filter other) {
return this.filter.areSerializedFieldsEqual(other);
}
}
What I mean is that filterKeyValue in the way i have it now, return the right
results but only the fields that were not originally skipped.
So for example, if i have two rows each one with two fields
Row 1
Name: Bill
Surname: Gates
Row 2
Name: Steve
Surname: Jobs
And I want to query for Rows that doesn't have Name 'Bill'
NOT (Name='Bill')
What I get as result from Hbase with this NotFilter is
Row 2
Surname: Jobs
I suppose it's related to the cell "Name: Steve" skipped in the first place
(before reversing the ReturnCode).
Best,
________________________________
De: Ted Yu <[email protected]>
Enviado: lunes, 02 de enero de 2017 06:31 p.m.
Para: [email protected]
Asunto: Re: Is it possible to implement a NOT filter in Hbase?
bq. the cell/value that was originally skip is not return
Can you be a bit more specific (with a concrete example) : the skipped cell
would not be returned (as indicated by the ReturnCode).
Thanks
On Mon, Jan 2, 2017 at 1:06 PM, Carl M <[email protected]> wrote:
> Hi Ted,
>
>
> I tried your suggestion, unfortunately it doesn't work as expected. I
> don't fully understand FilterList, but if a cell value was skip and I
> reverse the ReturnCode, i get the right row but the cell/value that was
> originally skip is not return.
>
> I also tried reversing only filterRow() method of FilterList, but I got
> the same behaviour (the original cell/value missing).
>
>
> Best,
>
>
> ________________________________
> De: Ted Yu <[email protected]>
> Enviado: viernes, 30 de diciembre de 2016 12:56 p.m.
> Para: [email protected]
> Asunto: Re: Is it possible to implement a NOT filter in Hbase?
>
> I think the ReturnCode opposite INCLUDE_AND_NEXT_COL is NEXT_COL : you're
> not interested in any version of the current Cell.
>
> Cheers
>
> On Fri, Dec 30, 2016 at 4:53 AM, Carl M <[email protected]> wrote:
>
> > Thanks Ted! Great idea replacing the value in filterKeyValue. Although
> I'm
> > not quite sure looking at FilterList code if only INCLUDE/SKIP should be
> > replaced, and which should be the correct replacement for
> > INCLUDE_AND_NEXT_COL. What do you think? If not maybe i should try to
> > implement DeMorgan's law but I think it would be harder.
> >
> >
> > Best,
> >
> > ________________________________
> > De: Ted Yu <[email protected]>
> > Enviado: jueves, 29 de diciembre de 2016 06:10 p.m.
> > Para: [email protected]
> > Asunto: Re: Is it possible to implement a NOT filter in Hbase?
> >
> > You can try negating the ReturnCode from filterKeyValue() (at the root of
> > FilterList):
> >
> > abstract public ReturnCode filterKeyValue(final Cell v) throws
> > IOException;
> >
> > INCLUDE -> SKIP
> >
> > SKIP -> INCLUDE
> >
> > Alternatively, you can use De Morgan's law to transfer the condition:
> >
> > NOT (a = '123' AND b = '456') becomes
> >
> > (NOT a = '123') OR (b = '456')
> >
> > On Thu, Dec 29, 2016 at 12:56 PM, Carl M <[email protected]>
> wrote:
> >
> > > Hi guys
> > >
> > >
> > > I'm trying to implement some kind of NOT filter in Hbase, but don't
> know
> > > if possible, I'm playing with FilterIfMissing and FilterList.Operator
> but
> > > without luck.
> > >
> > >
> > > I know how to return rows not having a specific column, but I mean
> > > something like returning rows NOT fullfilling a condition, where
> > condition
> > > could be not only a SingleColumnValueFilter but a combined condition
> with
> > > FilterList. In SQL would be something like this for example
> > >
> > >
> > > SELECT * FROM table WHERE NOT (a = '123' AND b = '456');
> > >
> > >
> > > Thanks in advance,
> > >
> >
>
