# What causes reads hotspot

+ Table for high-frequency access
+ SQL statement execution plan is not reasonable
+ Index scans with sequential growth properties
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- High-frequency access to some subtables causes hot spots: for example, configuration tables
- SQL execution plan is not reasonable
  - Missing indexes, unnecessary full table scan
  - Multiple indexes exist because the wrong index scan was selected due to statistics or CBO optimizer issues
- Index scans with sequential growth attributes, such as indexes for time-dependent column