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