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An important basic work in data governance is to analyze the blood relationship of data in the organization. With complete data kinship, we can use it for data traceability, impact analysis of table and field changes, proof of data compliance, inspection of data quality, etc. The methods of analyzing blood relationship of data are mainly divid ...

Source: segmentfault.com/a/1190000203866 background The company has a channel system, which is specially connected with three-party channels. There is no business logic. It mainly works on message conversion and parameter verification, which plays a connecting role. Recently, after optimizing the response time of the interface and the code ...

This paper combs and summarizes the parameter meaning and use of spark.sql.hive.caseSensitiveInferenceMode of spark 1. Parameter meaning Spark 2.1.1 introduces a new configuration item: spark.sql.hive.caseSensitiveInferenceMode. The default value is NEVER_INFER, maintain behavior consistent with spark 2.1.0. However, Spark 2.2.0 changes the de ...

MySQL learning notes station B DAY01 1. What is a database? What is a database management system? What is SQL? What is the relationship between them? Database: English words DataBase，abbreviation DB. A combination of files that store data in a format. As the name suggests: a warehouse for storing data is actually a pile of files. Stored i ...

Simple queries and inserted statements Simple query statement If we want to see what data has been stored in a table, we can use the following statement: SELECT * FROM Table name; For example, we want to see the first created earlier_ The data in the table can be written as follows: mysql> SELECT * FROM first_table; Empty set (0.01 sec ...

1, Database operation 1.1 create database Using sql statements to create Syntax: create database database name charset utf8; For example, create a database named test1 create database test1;Create using the graphical interface Navicat Select connection - right click to select "New Database", enter the database name, and click ok ...

1. Core structure and conceptThe Validator process provided by calculate is extremely complex, but to sum up, it mainly does one thing: verify whether the semantics of each SqlNode is correct in combination with metadata. These semantics include:Verify whether the table name exists;Whether the selected column exists in the corresponding table a ...

3, Query operation ▎ [3.1] which databases in hive are queried show databases; Before creating other databases, hive will provide a default database for us to use default   When operating HiveQL, all operations are performed in the default data without specifying the database. The database name and table name of hive are not case sensi ...

Query analysis and tuning backgroundIn the process of using the database, we often encounter the sudden slow down of SQL due to the following problems:Select wrong indexSelect the wrong connection orderRange queries use different quick optimization strategiesExecution method change of sub query selectionChange of policy mode of semi connection ...

Chapter 57 SQL command INTO A SELECT clause that specifies that the selected value is stored in the host variable. outline INTO :hostvar1 [,:hostvar2]... parameter : hostvar1 - the output host variable declared in the host language. When specified in the INTO clause, the variable name is preceded by a colon (:). Host variables ...