The principle of SQL parsing based on simple SQL statement and its application in big data

based on Simple SQL Statement of SQL analytic principle and its application in big Data

Li Wanhong

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SQL syntax parsing is usually based on Lex, yacc > based on analysis, the performance is not high. Assuming that parsing is based on an SQL statement that does not have subqueries, the speed is much higher, and the principle is explained here.

General SQL statements are complex, including multiple layers of nesting. But there are rules to follow. It is characterized by the same basic pattern of all statements, that is, a simple statement of the SELECT from WHERE type. Therefore, the ability to parse nested statements into such simple statements by article. Because the syntax of the SQL statement is the same. So we can parse the statement by recursive method, and parse the SQL statement into several simple sub - SQL statements. These sub-SQL statements are then parsed by a single method . This process. The algorithm is simple and effective. Greatly improves performance and is a revolutionary new way of thinking about SQL parsing.

Big data is usually used HBASE wait NOSQL , for SQL very inconvenient for development. For this reason, it is useful to use a distributed relational database to preserve big data, such as using ORACLE,MYSQL to save a table library to multiple databases, This allows for the processing of massive amounts of data and for traditional programming, supporting MYBATIS,SPRING,HIBERNATE . Development is extremely convenient.

The corresponding difficulty is the uniqueness of the ID of each library table and the processing of the SQL statement.

for ID the uniqueness of the solution is not difficult, the key lies in the distributed SQL the processing.

With the advent of big data software such as SPARK, the processing of distributed data is justified.

can useSPARKto process the distributed data. So how do we get this data? To this end, the proposedSQLThe Analytic principleSQLstatement to parse a complexSQLthe statement resolves to a much simplerSQLstatements, such asSELECT a.*form USER A WHERE a.id>222, and then find it through a data dictionaryUSERThe corresponding sub-library, run the query on each sub-library, and then use the results of each querySPARKprocessing, for other sub-SQLstatement, and then according to the masterSQLthe conditions of the statement are as followsJOIN,GROUP by,ORDER byand so on all the query data for the Operation summary processing, and finally return the results.

In short, by getting each simple sub- SQL statement for parsing or statement decomposition. is a good and effective way. Simple and ingenious to overcome a common problem, especially for the use of high-efficiency database processing Big Data has special significance, it lays a cornerstone. This is an extremely effective way to solve this problem. Worth the application.

2014-10-17

The principle of SQL parsing based on simple SQL statement and its application in big data