Transaction code ST04 is used to shows detail of the database behave & usage, both history and current time.
• Data buffer cache size & quality must be above 95% [meaning less physical read from disk]
• User/Recursive Call > 2 [Recursive call will get more over time]
• Read/User Call < 30 [> 30 means expensive SQL statements]
• Time/User Call < 15ms
• Busy time & CPU time ratio 60:40 ratio. Higher ratio means tuning required
• Sort sections. It should be less than 0.1% of total sorts.
• Shared pool statistics. DD (data dictionary) cache quality should be more than 99%, similarly the SQL area get ratio.
• Instance performance. Soft parse ratio max value is 1 which is not possible because at least once the SQL is hard parsed and then soft parsed in its next executions. But this must be as close as possible to 1 for a healthy system. Similarly there is another fact which is in-memory sort ratio; this is for a healthy system should have higher values. In fact the less the disk sorts the better.
