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Sean Busbey updated HBASE-22969: -------------------------------- Issue Type: New Feature (was: Improvement) > A new binary component comparator(BinaryComponentComparator) to perform > comparison of arbitrary length and position > ------------------------------------------------------------------------------------------------------------------- > > Key: HBASE-22969 > URL: https://issues.apache.org/jira/browse/HBASE-22969 > Project: HBase > Issue Type: New Feature > Components: Filters > Reporter: Udai Bhan Kashyap > Assignee: Udai Bhan Kashyap > Priority: Minor > Attachments: HBASE-22969.0003.patch, HBASE-22969.0004.patch, > HBASE-22969.0005.patch, HBASE-22969.0006.patch, HBASE-22969.0007.patch, > HBASE-22969.0008.patch, HBASE-22969.0009.patch, HBASE-22969.0010.patch, > HBASE-22969.0011.patch, HBASE-22969.HBASE-22969.0001.patch, > HBASE-22969.master.0001.patch > > > Lets say you have composite key: a+b+c+d. And for simplicity assume that > a,b,c, and d all are 4 byte integers. > Now, if you want to execute a query which is semantically same to following > sql: > {{"SELECT * from table where a=1 and b > 10 and b < 20 and c > 90 and c < 100 > and d=1"}} > The only choice you have is to do client side filtering. That could be lots > of unwanted data going through various software components and network. > Solution: > We can create a "component" comparator which takes the value of the > "component" and its relative position in the key to pass the 'Filter' > subsystem of the server: > {code} > FilterList filterList = new FilterList(FilterList.Operator.MUST_PASS_ALL); > int bOffset = 4; > byte[] b10 = Bytes.toBytes(10); > Filter b10Filter = new RowFilter(CompareFilter.CompareOp.GREATER, > new BinaryComponentComparator(b10,bOffset)); > filterList.addFilter(b10Filter); > byte[] b20 = Bytes.toBytes(20); > Filter b20Filter = new RowFilter(CompareFilter.CompareOp.LESS, > new BinaryComponentComparator(b20,bOffset)); > filterList.addFilter(b20Filter); > int cOffset = 8; > byte[] c90 = Bytes.toBytes(90); > Filter c90Filter = new RowFilter(CompareFilter.CompareOp.GREATER, > new BinaryComponentComparator(c90,cOffset)); > filterList.addFilter(c90Filter); > byte[] c100 = Bytes.toBytes(100); > Filter c100Filter = new RowFilter(CompareFilter.CompareOp.LESS, > new BinaryComponentComparator(c100,cOffset)); > filterList.addFilter(c100Filter); > in dOffset = 12; > byte[] d1 = Bytes.toBytes(1); > Filter dFilter = new RowFilter(CompareFilter.CompareOp.EQUAL, > new BinaryComponentComparator(d1,dOffset)); > filterList.addFilter(dFilter); > //build start and end key for scan > int aOffset = 0; > byte[] startKey = new byte[16]; //key size with four ints > Bytes.putInt(startKey,aOffset,1); //a=1 > Bytes.putInt(startKey,bOffset,11); //b=11, takes care of b > 10 > Bytes.putInt(startKey,cOffset,91); //c=91, > Bytes.putInt(startKey,dOffset,1); //d=1, > byte[] endKey = new byte[16]; > Bytes.putInt(endKey,aOffset,1); //a=1 > Bytes.putInt(endKey,bOffset,20); //b=20, takes care of b < 20 > Bytes.putInt(endKey,cOffset,100); //c=100, > Bytes.putInt(endKey,dOffset,1); //d=1, > //setup scan > Scan scan = new Scan(startKey,endKey); > scan.setFilter(filterList); > //The scanner below now should give only desired rows. > //No client side filtering is required. > ResultScanner scanner = table.getScanner(scan); > {code} > The comparator can be used with any filter which makes use of > ByteArrayComparable. Most notably it can be used with ValueFilter to filter > out KV based on partial comparison of 'values' : > {code} > byte[] partialValue = Bytes.toBytes("partial_value"); > int partialValueOffset = > Filter partialValueFilter = new > ValueFilter(CompareFilter.CompareOp.GREATER, > new BinaryComponentComparator(partialValue,partialValueOffset)); > {code} > Which in turn can be combined with RowFilter to create a poweful predicate: > {code} > RowFilter rowFilter = new RowFilter(GREATER, new > BinaryComponentComparator(Bytes.toBytes("a"),1); > FilterLiost fl = new FilterList > (MUST_PASS_ALL,rowFilter,partialValueFilter); > {code} -- This message was sent by Atlassian Jira (v8.3.4#803005)