HUDI_META

描述

hudi_meta 表函数（table-valued-function,tvf），可以用于读取 hudi 表的各类元数据信息，如操作历史、表的时间线、文件元数据等。

语法

HUDI_META(
    "table" = "<table>", 
    "query_type" = "<query_type>"
  );

必填参数

hudi_meta 表函数 tvf 中的每一个参数都是一个 "key"="value" 对

字段	说明
<table>	完整的表名，需要按照目录名。库名。表名的格式，填写需要查看的 Hudi 表名。
<query_type>	想要查看的元数据类型，目前仅支持 timeline。

示例（Examples）

• 读取并访问 hudi 表格式的 timeline 元数据。

  select * from hudi_meta("table" = "ctl.db.tbl", "query_type" = "timeline");
  

• 可以配合desc function使用

  desc function hudi_meta("table" = "ctl.db.tbl", "query_type" = "timeline");

• 查看 hudi 表的 timeline

  select * from hudi_meta("table" = "hudi_ctl.test_db.test_tbl", "query_type" = "timeline");

  +-------------------+--------+--------------------------+-----------+-----------------------+
  | timestamp         | action | file_name                | state     | state_transition_time |
  +-------------------+--------+--------------------------+-----------+-----------------------+
  | 20240724195843565 | commit | 20240724195843565.commit | COMPLETED | 20240724195844269     |
  | 20240724195845718 | commit | 20240724195845718.commit | COMPLETED | 20240724195846653     |
  | 20240724195848377 | commit | 20240724195848377.commit | COMPLETED | 20240724195849337     |
  | 20240724195850799 | commit | 20240724195850799.commit | COMPLETED | 20240724195851676     |
  +-------------------+--------+--------------------------+-----------+-----------------------+

• 根据 timestamp 字段筛选

  select * from hudi_meta("table" = "hudi_ctl.test_db.test_tbl", "query_type" = "timeline") where timestamp = 20240724195843565;

  +-------------------+--------+--------------------------+-----------+-----------------------+
  | timestamp         | action | file_name                | state     | state_transition_time |
  +-------------------+--------+--------------------------+-----------+-----------------------+
  | 20240724195843565 | commit | 20240724195843565.commit | COMPLETED | 20240724195844269     |
  +-------------------+--------+--------------------------+-----------+-----------------------+