High level line of Oracle

I have been reading a question and a statistical statement over the past few days.ProgramSuddenly, the data volume is abnormal. I checked the data from the beginning and found that there was no problem with the program and configuration, but the result was incorrect. However, I found that there was still a large number of stored files in the program, it may be because the data has not been fully written into the database, but what caused it? I thought that some files were too large and too slow to be written into the database, but later I found that the database was still a problem, it takes a long time for a temp table to query empty tables. The problem is found. If you do not understand why, you can find a conclusion on the net that the high water level of Oracle cannot be lowered when you delete the data, and the query will be slow.

The final solution is to perform a truncate after the processing is completed, so that the high water level line is lowered, and finally the data is properly imported into the database.

 

 

Appendix: A comprehensive blog on hwm

Http://blog.chinaunix.net/u2/60332/showart_495441.html