Vertical splitting is a technique for splitting a table by columns, dividing the columns in a table into multiple tables, and each table contains only a part of the columns. The specific method is as follows:
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Identify commonly used and uncommonly used columns: By monitoring and analyzing the system, commonly used and uncommonly used columns can be identified.
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Create multiple tables: Create multiple tables based on commonly used and uncommonly used columns. Frequently used columns are stored in one table, and less frequently used columns are stored in another table.
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Use association query: When querying, use association query to connect multiple tables to obtain complete data. Association queries can be performed using JOIN statements or subqueries.
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Regularly update data: Since data is scattered in multiple tables, it is necessary to update data regularly to ensure data consistency.
Vertical segmentation can improve query efficiency and reduce the amount of query data, but it also increases system complexity and maintenance costs. Therefore, when performing vertical segmentation, trade-offs need to be made on a case-by-case basis. Here are some factors to consider:
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Database size: Vertical splitting needs to be considered only when the amount of data is relatively large.
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Query frequency: Only when the query frequency of certain columns is relatively low, vertical splitting needs to be considered.
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System complexity and maintenance cost: Vertical segmentation will increase system complexity and maintenance cost, and it is necessary to consider whether it is worth investing in these costs.
Therefore, when performing vertical segmentation, it is necessary to fully consider various factors and make reasonable trade-offs.