fix(wsr): low probability that wsr report generation fails due to conflict with timed task of dropping outdated data · Pull Request !1611 · openEuler/cantian

**[Background]**
There is a low probability that the wsr report generation process would fail with the message "Table has been dropped or truncate".
![输入图片说明](https://foruda.gitee.com/images/1744957916496172682/c37259c9_7713365.png "屏幕截图")

**[Root Cause]**
Wsr report generation process is essentially a pile of selection statements from a number of wsr-related tables. There is a timed task WSR$DROP_SNAPSHOT_TIME that, by default, is executed once a day, and would clear the outdated WSR-related data that is, by default, more than two days old. These wsr-related data are put into partition tables according to the day when it is generated, and the snapshot-dropping process would drop the outdated partitions to clean the outdated data. When the selection process is half-way undergone when the snapshot-dropping process is triggered, there is a chance that the partition which the selection process is visiting is dropped by the snapshot-dropping process - because selection processes do not add locks to the tables that are planned to be visited - and thus the error would occur.

**[Changes Made]**
Add a share lock before wsr report generation process so that processes like drop partition would be temporarily held.

**[Test Result]**
DDLs regarding tables in questions are successfully held up during report generation process.
![输入图片说明](https://foruda.gitee.com/images/1745069380494529428/8621a215_7713365.png "屏幕截图")

GVPopenEuler/cantian

搜索帮助

GVP openEuler/cantian