CHECK BLOB CHECKSUM
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CHECK BLOB CHECKSUM checks for and displays columnstore blob file corruptions.
Syntax
CHECK BLOB CHECKSUM [WITH REPAIR[FORCE]];Arguments
-
When High Availability (HA) is enabled, the
WITH REPAIRoption will repair the corruption by replacing the corrupt blob with a valid copy (HA replica) from another partition.When HA is not enabled, the corruption cannot be repaired. -
The
WITH REPAIR FORCEoption deletes the metadata for the corrupt blob.While this will allow the table to be queried, it will also result in data loss.
Example
This is a simple use showing how the output of CHECK BLOB CHECKSUM displays corruption in columnstore blob files.
CHECK BLOB CHECKSUM;
+---------+-----------+-------+----------+-------+---------------------+----------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------------+
| node_id | Host | Port | Database | Table | Filename | Reason | Repair operations |
+---------+-----------+-------+----------+-------+---------------------+----------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------------+
| 2 | 127.0.0.1 | 10001 | db3 | rtab | blobs/22/0/0/10_29 | File has incorrect checksum. Actual checksum 0x29072b55, expected checksum 0xe6ac67b6. | copy blob file from replica on '127.0.0.1':10000 |
| 2 | 127.0.0.1 | 10001 | db3 | rtab | blobs/22/0/0/10_58 | Missing file | copy blob file from replica on '127.0.0.1':10000 |
| 2 | 127.0.0.1 | 10001 | db3 | rtab | blobs/22/0/0/10_88 | File has incorrect size. Actual size 49, expected size 44 | Remove file (a copy of the file is avaliable on 127.0.0.1:10000, but its not valid. Hit error 1017) |
| 2 | 127.0.0.1 | 10001 | db3 | rtab | blobs/22/0/0/10_112 | File has incorrect size. Actual size 51, expected size 46 | copy blob file from replica on '127.0.0.1':10000 |
| 2 | 127.0.0.1 | 10001 | db3 | rtab | blobs/22/0/0/10_118 | File has incorrect size. Actual size 49, expected size 44 | copy blob file from replica on '127.0.0.1':10000 |
| 2 | 127.0.0.1 | 10001 | db3 | rtab | blobs/22/0/0/10_191 | Missing file | copy blob file from replica on '127.0.0.1':10000 |
| 2 | 127.0.0.1 | 10001 | db3 | rtab | blobs/22/0/0/10_203 | File has incorrect checksum. Actual checksum 0xf6aac90f, expected checksum 0x390185ec. | copy blob file from replica on '127.0.0.1':10000 |
| 2 | 127.0.0.1 | 10001 | db3 | rtab | blobs/22/0/0/10_208 | Missing file | copy blob file from replica on '127.0.0.1':10000 |
| 2 | 127.0.0.1 | 10001 | db3 | rtab | blobs/22/0/0/10_214 | File has incorrect checksum. Actual checksum 0x205df634, expected checksum 0xdb081c6a. | copy blob file from replica on '127.0.0.1':10000 |
| 2 | 127.0.0.1 | 10001 | db3 | rtab | blobs/22/0/0/10_232 | File has incorrect checksum. Actual checksum 0x460d1e1a, expected checksum 0xbbab2e04. | Remove file (a copy of the file is avaliable on 127.0.0.1:10000, but its not valid. Hit error 1017) |
| 2 | 127.0.0.1 | 10001 | db3 | rtab | blobs/22/0/0/10_238 | File has incorrect checksum. Actual checksum 0x31705cf0, expected checksum 0xca25b6ae. | copy blob file from replica on '127.0.0.1':10000 |Last modified: January 26, 2024