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MRS-operation-guide-lts/doc/component-operation-guide-lts/source/using_hive/customizing_row_separators.rst
proposalbot d31d5b10fe Changes to mrs_operation-guide-lts from docs/doc-exports#515 (MRS comp-lts 2.0.3 
Reviewed-by: Kacur, Michal <michal.kacur@t-systems.com>
Co-authored-by: proposalbot <proposalbot@otc-service.com>
Co-committed-by: proposalbot <proposalbot@otc-service.com>
2023-01-19 16:53:12 +00:00

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mrs_01_0955.html

Customizing Row Separators

Scenario

In most cases, a carriage return character is used as the row delimiter in Hive tables stored in text files, that is, the carriage return character is used as the terminator of a row during queries. However, some data files are delimited by special characters, and not a carriage return character.

MRS Hive allows you to use different characters or character combinations to delimit rows of Hive text data. When creating a table, set inputformat to SpecifiedDelimiterInputFormat, and set the following parameter before search each time. Then the table data is queried by the specified delimiter.

set hive.textinput.record.delimiter='';

Note

The Hue component of the current version does not support the configuration of multiple separators when files are imported to a Hive table.

Procedure

  1. Specify inputFormat and outputFormat when creating a table.

    CREATE [TEMPORARY] [EXTERNAL] TABLE [IF NOT EXISTS] [db_name.]table_name [(col_name data_type [COMMENT col_comment], ...)] [ROW FORMAT row_format] STORED AS inputformat 'org.apache.hadoop.hive.contrib.fileformat.SpecifiedDelimiterInputFormat' outputformat 'org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat'

  2. Specify the delimiter before search.

    set hive.textinput.record.delimiter='!@!'

    Hive will use '!@!' as the row delimiter.