首页    技术博客    PHP教程    数据库技术    前端开发   HTML5    Nginx    php论坛
新用户注册 | 会员登录
加入会员，解锁专属内容
取消
热门标签 | HotTags
当前位置:  开发笔记 > 编程语言 > 正文

HBaseThrift过滤语法

作者：范二小姐儿 | 来源：互联网 | 2023-05-19 05:34
摘抄自hbaserefguide0.94；在写本文的时候，hbaserefguide已经更新到1.2及2.0了，但是个人感觉Thrift过滤语法部分写得都没有0.94的好，省掉了exam

摘抄自hbase ref guide 0.94；

在写本文的时候，hbase ref guide已经更新到1.2及2.0了，但是个人感觉Thrift过滤语法部分写得都没有0.94的好，省掉了example，看起来很不方便，也不便于在hbase shell中进行调试，因而复制一份过来，以免以后找不到；

-------------

10.3. Thrift

Currently most of the documentation on Thrift exists in the Apache HBase Wiki on Thrift.

10.3.1. Filter Language

10.3.1.1. Use Case

Note: this feature was introduced in Apache HBase 0.92

This allows the user to perform server-side filtering when accessing HBase over Thrift. The user specifies a filter via a string. The string is parsed on the server to construct the filter

10.3.1.2. General Filter String Syntax

A simple filter expression is expressed as: “FilterName (argument, argument, ... , argument)”

You must specify the name of the filter followed by the argument list in parenthesis. Commas separate the individual arguments

If the argument represents a string, it should be enclosed in single quotes.

If it represents a boolean, an integer or a comparison operator like <, >, != etc. it should not be enclosed in quotes

The filter name must be one word. All ASCII characters are allowed except for whitespace, single quotes and parenthesis.

The filter’s arguments can contain any ASCII character. If single quotes are present in the argument, they must be escaped by a preceding single quote

10.3.1.3. Compound Filters and Operators

Currently, two binary operators – AND/OR and two unary operators – WHILE/SKIP are supported.

Note: the operators are all in uppercase

AND – as the name suggests, if this operator is used, the key-value must pass both the filters

OR – as the name suggests, if this operator is used, the key-value must pass at least one of the filters

SKIP – For a particular row, if any of the key-values don’t pass the filter condition, the entire row is skipped

WHILE - For a particular row, it continues to emit key-values until a key-value is reached that fails the filter condition

Compound Filters: Using these operators, a hierarchy of filters can be created. For example: “(Filter1 AND Filter2) OR (Filter3 AND Filter4)”

10.3.1.4. Order of Evaluation

Parenthesis have the highest precedence. The SKIP and WHILE operators are next and have the same precedence.The AND operator has the next highest precedence followed by the OR operator.

For example:

A filter string of the form:“Filter1 AND Filter2 OR Filter3” will be evaluated as:“(Filter1 AND Filter2) OR Filter3”

A filter string of the form:“Filter1 AND SKIP Filter2 OR Filter3” will be evaluated as:“(Filter1 AND (SKIP Filter2)) OR Filter3”

10.3.1.5. Compare Operator

A compare operator can be any of the following:

  1. LESS (<)

  2. LESS_OR_EQUAL (<=)

  3. EQUAL (=)

  4. NOT_EQUAL (!=)

  5. GREATER_OR_EQUAL (>=)

  6. GREATER (>)

  7. NO_OP (no operation)

The client should use the symbols (<, <=, =, !=, >, >=) to express compare operators.

10.3.1.6. Comparator

A comparator can be any of the following:

  1. BinaryComparator - This lexicographically compares against the specified byte array using Bytes.compareTo(byte[], byte[])

  2. BinaryPrefixComparator - This lexicographically compares against a specified byte array. It only compares up to the length of this byte array.

  3. RegexStringComparator - This compares against the specified byte array using the given regular expression. Only EQUAL and NOT_EQUAL comparisons are valid with this comparator

  4. SubStringComparator - This tests if the given substring appears in a specified byte array. The comparison is case insensitive. Only EQUAL and NOT_EQUAL comparisons are valid with this comparator

The general syntax of a comparator is: ComparatorType:ComparatorValue

The ComparatorType for the various comparators is as follows:

  1. BinaryComparator - binary

  2. BinaryPrefixComparator - binaryprefix

  3. RegexStringComparator - regexstring

  4. SubStringComparator - substring

The ComparatorValue can be any value.

Example1: >, 'binary:abc' will match everything that is lexicographically greater than "abc"

Example2: =, 'binaryprefix:abc' will match everything whose first 3 characters are lexicographically equal to "abc"

Example3: !=, 'regexstring:ab*yz' will match everything that doesn't begin with "ab" and ends with "yz"

Example4: =, 'substring:abc123' will match everything that begins with the substring "abc123"

10.3.1.7. Example PHP Client Program that uses the Filter Language

', );
   $hbase->open();
   $client = $hbase->getClient();
   $result = $client->scannerOpenWithFilterString('table_name', "(PrefixFilter ('row2') AND (QualifierFilter (>=, 'binary:xyz'))) AND (TimestampsFilter ( 123, 456))");
   $to_print = $client->scannerGetList($result,1);
   while ($to_print) {
      print_r($to_print);
      $to_print = $client->scannerGetList($result,1);
    }
   $client->scannerClose($result);
?>

　　

10.3.1.8. Example Filter Strings 

  • “PrefixFilter (‘Row’) AND PageFilter (1) AND FirstKeyOnlyFilter ()” will return all key-value pairs that match the following conditions:

    1) The row containing the key-value should have prefix “Row”

    2) The key-value must be located in the first row of the table

    3) The key-value pair must be the first key-value in the row 

  • “(RowFilter (=, ‘binary:Row 1’) AND TimeStampsFilter (74689, 89734)) OR ColumnRangeFilter (‘abc’, true, ‘xyz’, false))” will return all key-value pairs that match both the following conditions:

    1) The key-value is in a row having row key “Row 1”

    2) The key-value must have a timestamp of either 74689 or 89734.

    Or it must match the following condition:

    1) The key-value pair must be in a column that is lexicographically >= abc and

  • “SKIP ValueFilter (0)” will skip the entire row if any of the values in the row is not 0

 

10.3.1.9. Individual Filter Syntax

  1. KeyOnlyFilter

    Description: This filter doesn’t take any arguments. It returns only the key component of each key-value.

    Syntax: KeyOnlyFilter ()

    Example: "KeyOnlyFilter ()"

  2. FirstKeyOnlyFilter

    Description: This filter doesn’t take any arguments. It returns only the first key-value from each row.

    Syntax: FirstKeyOnlyFilter ()

    Example: "FirstKeyOnlyFilter ()"

  3. PrefixFilter

    Description: This filter takes one argument – a prefix of a row key. It returns only those key-values present in a row that starts with the specified row prefix

    Syntax: PrefixFilter (‘’)

    Example: "PrefixFilter (‘Row’)"

  4. ColumnPrefixFilter

    Description: This filter takes one argument – a column prefix. It returns only those key-values present in a column that starts with the specified column prefix. The column prefix must be of the form: “qualifier”

    Syntax:ColumnPrefixFilter(‘’)

    Example: "ColumnPrefixFilter(‘Col’)"

  5. MultipleColumnPrefixFilter

    Description: This filter takes a list of column prefixes. It returns key-values that are present in a column that starts with any of the specified column prefixes. Each of the column prefixes must be of the form: “qualifier”

    Syntax:MultipleColumnPrefixFilter(‘’, ‘’, …, ‘’)

    Example: "MultipleColumnPrefixFilter(‘Col1’, ‘Col2’)"

  6. ColumnCountGetFilter

    Description: This filter takes one argument – a limit. It returns the first limit number of columns in the table

    Syntax: ColumnCountGetFilter (‘’)

    Example: "ColumnCountGetFilter (4)"

  7. PageFilter

    Description: This filter takes one argument – a page size. It returns page size number of rows from the table.

    Syntax: PageFilter (‘’)

    Example: "PageFilter (2)"

  8. ColumnPaginationFilter

    Description: This filter takes two arguments – a limit and offset. It returns limit number of columns after offset number of columns. It does this for all the rows

    Syntax: ColumnPaginationFilter(‘’, ‘’)

    Example: "ColumnPaginationFilter (3, 5)"

  9. InclusiveStopFilter

    Description: This filter takes one argument – a row key on which to stop scanning. It returns all key-values present in rows up to and including the specified row

    Syntax: InclusiveStopFilter(‘’)

    Example: "InclusiveStopFilter ('Row2')"

  10. TimeStampsFilter

    Description: This filter takes a list of timestamps. It returns those key-values whose timestamps matches any of the specified timestamps

    Syntax: TimeStampsFilter (, , ... ,)

    Example: "TimeStampsFilter (5985489, 48895495, 58489845945)"

  11. RowFilter

    Description: This filter takes a compare operator and a comparator. It compares each row key with the comparator using the compare operator and if the comparison returns true, it returns all the key-values in that row

    Syntax: RowFilter (, ‘’)

    Example: "RowFilter (<=, ‘xyz)"

  12. Family Filter

    Description: This filter takes a compare operator and a comparator. It compares each qualifier name with the comparator using the compare operator and if the comparison returns true, it returns all the key-values in that column

    Syntax: QualifierFilter (, ‘’)

    Example: "QualifierFilter (=, ‘Column1’)"

  13. QualifierFilter

    Description: This filter takes a compare operator and a comparator. It compares each qualifier name with the comparator using the compare operator and if the comparison returns true, it returns all the key-values in that column

    Syntax: QualifierFilter (,‘’)

    Example: "QualifierFilter (=,‘Column1’)"

  14. ValueFilter

    Description: This filter takes a compare operator and a comparator. It compares each value with the comparator using the compare operator and if the comparison returns true, it returns that key-value

    Syntax: ValueFilter (,‘’)

    Example: "ValueFilter (!=, ‘Value’)"

  15. DependentColumnFilter

    Description: This filter takes two arguments – a family and a qualifier. It tries to locate this column in each row and returns all key-values in that row that have the same timestamp. If the row doesn’t contain the specified column – none of the key-values in that row will be returned.

    The filter can also take an optional boolean argument – dropDependentColumn. If set to true, the column we were depending on doesn’t get returned.

    The filter can also take two more additional optional arguments – a compare operator and a value comparator, which are further checks in addition to the family and qualifier. If the dependent column is found, its value should also pass the value check and then only is its timestamp taken into consideration

    Syntax: DependentColumnFilter (‘’, ‘’, , , ‘

    Syntax: DependentColumnFilter (‘’, ‘’, )

    Syntax: DependentColumnFilter (‘’, ‘’)

    Example: "DependentColumnFilter (‘conf’, ‘blacklist’, false, >=, ‘zebra’)"

    Example: "DependentColumnFilter (‘conf’, 'blacklist', true)"

    Example: "DependentColumnFilter (‘conf’, 'blacklist')"

  16. SingleColumnValueFilter

    Description: This filter takes a column family, a qualifier, a compare operator and a comparator. If the specified column is not found – all the columns of that row will be emitted. If the column is found and the comparison with the comparator returns true, all the columns of the row will be emitted. If the condition fails, the row will not be emitted.

    This filter also takes two additional optional boolean arguments – filterIfColumnMissing and setLatestVersionOnly

    If the filterIfColumnMissing flag is set to true the columns of the row will not be emitted if the specified column to check is not found in the row. The default value is false.

    If the setLatestVersionOnly flag is set to false, it will test previous versions (timestamps) too. The default value is true.

    These flags are optional and if you must set neither or both

    Syntax: SingleColumnValueFilter(, ‘’, ‘’, ‘’,, )

    Syntax: SingleColumnValueFilter(, ‘’, ‘’, ‘)

    Example: "SingleColumnValueFilter (<=, ‘abc’,‘FamilyA’, ‘Column1’, true, false)"

    Example: "SingleColumnValueFilter (<=, ‘abc’,‘FamilyA’, ‘Column1’)"

  17. SingleColumnValueExcludeFilter

    Description: This filter takes the same arguments and behaves same as SingleColumnValueFilter – however, if the column is found and the condition passes, all the columns of the row will be emitted except for the tested column value.

    Syntax: SingleColumnValueExcludeFilter(, '', '', '',, )

    Syntax: SingleColumnValueExcludeFilter(, '', '', '')

    Example: "SingleColumnValueExcludeFilter (‘<=’, ‘abc’,‘FamilyA’, ‘Column1’, ‘false’, ‘true’)"

    Example: "SingleColumnValueExcludeFilter (‘<=’, ‘abc’, ‘FamilyA’, ‘Column1’)"

  18. ColumnRangeFilter

    Description: This filter is used for selecting only those keys with columns that are between minColumn and maxColumn. It also takes two boolean variables to indicate whether to include the minColumn and maxColumn or not.

    If you don’t want to set the minColumn or the maxColumn – you can pass in an empty argument.

    Syntax: ColumnRangeFilter (‘’, , ‘’, )

    Example: "ColumnRangeFilter (‘abc’, true, ‘xyz’, false)"

 

---------------

注：

已知16.SingleColumnValueFilter和17.SingleColumnValueExcludeFilter的语法已经变掉，参数顺序调整为：

Syntax: SingleColumnValueFilter(‘’, ‘', , ‘’,)


推荐阅读
  • express

    Linux虚拟化部署中的VLAN配置方法详解

    本文详细介绍了在Linux虚拟化部署中进行VLAN配置的方法。首先要确认Linux系统内核是否已经支持VLAN功能，然后配置物理网卡、子网卡和虚拟VLAN网卡的关系。接着介绍了在Linux配置VLAN Trunk的步骤，包括将物理网卡添加到VLAN、检查添加的VLAN虚拟网卡信息以及重启网络服务等。最后，通过验证连通性来确认配置是否成功。 ... [详细]
  • io

    Android开发笔记：使用Picasso加载网络图片等比例缩放

    在Android开发中，使用Picasso库可以实现对网络图片的等比例缩放。本文介绍了使用Picasso库进行图片缩放的方法，并提供了具体的代码实现。通过获取图片的宽高，计算目标宽度和高度，并创建新图实现等比例缩放。 ... [详细]
  • 数组

    Redis数据结构之string应用场景解析

    本文介绍了Redis的基础数据结构string的应用场景，并以面试的形式进行问答讲解，帮助读者更好地理解和应用Redis。同时，描述了一位面试者的心理状态和面试官的行为。 ... [详细]
  • foreach

    Spring特性实现接口多类的动态调用详解

    Spring特性实现接口多类的动态调用详解
    本文详细介绍了如何使用Spring特性实现接口多类的动态调用。通过对Spring IoC容器的基础类BeanFactory和ApplicationContext的介绍，以及getBeansOfType方法的应用，解决了在实际工作中遇到的接口及多个实现类的问题。同时，文章还提到了SPI使用的不便之处，并介绍了借助ApplicationContext实现需求的方法。阅读本文，你将了解到Spring特性的实现原理和实际应用方式。 ... [详细]
  • python

    计算机网络初识及通信流程分析

    本文介绍了计算机网络的定义和通信流程，包括客户端编译文件、二进制转换、三层路由设备等。同时，还介绍了计算机网络中常用的关键词，如MAC地址和IP地址。 ... [详细]
  • express

    用SQL语句怎么把已存在的列加上IDENTITY(1,1)属性

    ALTERTABLE通过更改、添加、除去列和约束，或者通过启用或禁用约束和触发器来更改表的定义。语法ALTERTABLEtable{[ALTERCOLUMNcolu ... [详细]
  • express

    Express App如何提供不需要的静态文件？

    本文介绍了如何使用Express App提供静态文件，同时提到了一些不需要使用的文件，如package.json和/.ssh/known_hosts，并解释了为什么app.get('*')无法捕获所有请求以及为什么app.use(express.static(__dirname))可能会提供不需要的文件。 ... [详细]
  • ascii

    Python基础篇：315道题目及答案整理，帮助你检验学习成果

    本文整理了315道Python基础题目及答案，帮助读者检验学习成果。文章介绍了学习Python的途径、Python与其他编程语言的对比、解释型和编译型编程语言的简述、Python解释器的种类和特点、位和字节的关系、以及至少5个PEP8规范。对于想要检验自己学习成果的读者，这些题目将是一个不错的选择。请注意，答案在视频中，本文不提供答案。 ... [详细]
  • express

    微软评估和规划（MAP）的工具包介绍及应用实验手册

    微软评估和规划（MAP）的工具包介绍及应用实验手册
    本文介绍了微软评估和规划（MAP）的工具包，该工具包是一个无代理工具，旨在简化和精简通过网络范围内的自动发现和评估IT基础设施在多个方案规划进程。工具包支持库存和使用用于SQL Server和Windows Server迁移评估，以及评估服务器的信息最广泛使用微软的技术。此外，工具包还提供了服务器虚拟化方案，以帮助识别未被充分利用的资源和硬件需要成功巩固服务器使用微软的Hyper - V技术规格。 ... [详细]
  • object

    如何自行分析定位SAP BSP错误

    如何自行分析定位SAP BSP错误
    The“BSPtag”Imentionedintheblogtitlemeansforexamplethetagchtmlb:configCelleratorbelowwhichi ... [详细]
  • buffer

    C#生成随机数的三种方法及其问题分析

    本文介绍了C#中生成随机数的三种方法，并分析了其中存在的问题。首先介绍了使用Random类生成随机数的默认方法，但在高并发情况下可能会出现重复的情况。接着通过循环生成了一系列随机数，进一步突显了这个问题。文章指出，随机数生成在任何编程语言中都是必备的功能，但Random类生成的随机数并不可靠。最后，提出了需要寻找其他可靠的随机数生成方法的建议。 ... [详细]
  • python

    Thrift教程初级篇——RPC框架Thrift的安装环境变量配置与第一个实例

    本文介绍了RPC框架Thrift的安装环境变量配置与第一个实例，讲解了RPC的概念以及如何解决跨语言、c++客户端、web服务端、远程调用等需求。Thrift开发方便上手快，性能和稳定性也不错，适合初学者学习和使用。 ... [详细]
  • io

    iptables如何添加非对称的NAT规则段的解决方法

    本文介绍了如何使用iptables添加非对称的NAT规则段，以实现内网穿透和端口转发的功能。通过查阅相关文章，得出了解决方案，即当匹配的端口在映射端口的区间内时，可以成功进行端口转发。详细的操作步骤和命令示例也在文章中给出。 ... [详细]
  • int

    ASP.NET Tips: 获取插入记录的ID的方法详解

    本文详细介绍了在ASP.NET中获取插入记录的ID的几种方法，包括使用SCOPE_IDENTITY()和IDENT_CURRENT()函数，以及通过ExecuteReader方法执行SQL语句获取ID的步骤。同时，还提供了使用这些方法的示例代码和注意事项。对于需要获取表中最后一个插入操作所产生的ID或马上使用刚插入的新记录ID的开发者来说，本文提供了一些有用的技巧和建议。 ... [详细]
  • express

    Python正则表达式学习记录及常用方法

    Python正则表达式学习记录及常用方法
    本文记录了学习Python正则表达式的过程，介绍了re模块的常用方法re.search，并解释了rawstring的作用。正则表达式是一种方便检查字符串匹配模式的工具，通过本文的学习可以掌握Python中使用正则表达式的基本方法。 ... [详细]
author-avatar
范二小姐儿
这个家伙很懒，什么也没留下！
Tags | 热门标签
RankList | 热门文章
PHP1.CN | 中国最专业的PHP中文社区 | DevBox开发工具箱 | json解析格式化 |PHP资讯 | PHP教程 | 数据库技术 | 服务器技术 | 前端开发技术 | PHP框架 | 开发工具 | 在线工具
Copyright © 1998 - 2020 PHP1.CN. All Rights Reserved | 京公网安备 11010802041100号 | 京ICP备19059560号-4 | PHP1.CN 第一PHP社区 版权所有