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Editor to share with you what filters are commonly used in HBase, I believe most people do not know much about it, so share this article for your reference, I hope you can learn a lot after reading this article, let's go to know it!

1. Comparison filter

(1) compare filter operators

LESS

NO_OP excludes all

(2) comparators of commonly used comparison filters

BinaryComparator compares the specified byte array in byte index order, using Bytes.compareTo (byte [])

BinaryPrefixComparator is the same as before, except to compare whether the data on the left end is the same.

NullComparator determines whether the given one is empty or not

BitComparator bit-by-bit comparison

RegexStringComparator provides a regular comparator that only supports EQUAL and non-EQUAL

SubstringComparator determines whether the provided substring appears in the value

(3) the practical application of comparison filter.

3-1) Row key filter RowFilter

Filter filter = new RowFilter (CompareOp.LESS_OR_EQUAL,new BinaryComparator (Bytes.toBytes ("row-22")

Scan.setFilter (filter)

Filter filter1 = new RowFilter (CompareOp.EQUAL, new SubstringComparator ("- 5"))

Scan.setFilter (filter1)

3-2) column Family filter FamilyFilter

Filter filter1 = new FamilyFilter (CompareFilter.CompareOp.LESS, new BinaryComparator (Bytes.toBytes ("colfam3")

Scan.setFilter (filter1)

3-3) column filter QualifierFilter

Filter = new QualifierFilter (CompareFilter.CompareOp.LESS_OR_EQUAL, new BinaryComparator (Bytes.toBytes ("col-2")

Scan.setFilter (filter1)

3-4) value filter ValueFilter

Filter filter = new ValueFilter (CompareFilter.CompareOp.EQUAL, new SubstringComparator (".4"))

Scan.setFilter (filter1)

two。 Special filter

(1) prefix filter PrefixFilter-for row keys

Filter fileter = new PrefixFilter (Bytes.toBytes ("hello"))

Scan.setFilter (fileter)

(2) column prefix filter

Filter fileter = new ColumnPrefixFilter (Bytes.toBytes ("hello"))

Scan.setFilter (filter)

3. Regular expression filtering (RegexStringComparator)

Scan scan = new Scan ()

RegexStringComparator comp = new RegexStringComparator ("you."); / / string that begins with you

SingleColumnValueFilter filter = new SingleColumnValueFilter (Bytes.toBytes ("family"), Bytes.toBytes ("qualifier"), CompareOp.EQUAL, comp)

Scan.setFilter (filter)

4. SubStringComparator

Used to monitor whether a substring exists in a value and is not case-sensitive.

Scan scan = new Scan ()

SubstringComparator comp = new SubstringComparator ("1129"); / / find a string containing 1129

SingleColumnValueFilter filter = new SingleColumnValueFilter (Bytes.toBytes ("family"), Bytes.toBytes ("qualifier"), CompareOp.EQUAL, comp)

Scan.setFilter (filter)

5. Bloom filter BloomFilter

Introduction: there are many storefile of hbase, and you may need to traverse a lot of storefile when checking randomly. If you specify bloomfilter when creating a table, you can filter out a lot of storefile that do not comply with the rules when you query get (scan does not work) and improve query efficiency.

The above is all the contents of the article "what are the commonly used filters in HBase?" Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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