Oracle performance optimization operations: Summary, oracle Performance Optimization

Oracle performance optimization operations: Summary, oracle Performance Optimization

These articles about oracle performance optimization can be used in combination with each other. In addition, various methods are closely related to each other.

This kind of connection is consistent and may lead to conflicts. When a conflict occurs, you need to select it based on the actual situation. There is no fixed mode.

The final factor that determines the SQL optimization capability is the knowledge of ORACLE basics.

In addition, it is worth noting that with the passage of time and the accumulation and change of data, ORACLE's SQL statement execution plan will also change.

For example, the cost-based optimization method, with the increase of data size, the Optimizer may mistakenly use full table scan without selecting an index.

This may be because the statistical information is outdated and the analysis table is not analyzed in time after the data volume changes greatly;

However, if the table is not properly indexed after analysis, it is necessary to use the HINT prompt for SQL statements to force a reasonable index.

However, such HINT prompts cannot be abused, because this method is too complicated, lacks versatility and adaptability, and also increases the maintenance cost;

Relatively speaking, based on the right shift of the function, remove "IN, OR, <>, is not null", and break down complicated SQL statements, it IS "accurate to all corners of the world,

You can use it with confidence.

At the same time, optimization is not "once and for all" and must be adjusted accordingly as the situation changes.

When the database design changes, including modifying the table structure: adding, deleting, or renaming fields and indexes;

Business Logic changes: such as the query method and value range.

In this case, the original optimization must also be adjusted to meet the efficiency requirements.