Note: This article is only applicable when a user upgrades to a higher version of Pivotal Greenplum and then downgrades to below to 184.108.40.206, when checksum was introduced.
- Pivotal Greenplum (GPDB) 4.2.x, 4.3.x
- OS RHEL 6.x
Append only tables are inaccessible by the users and result with the following error.
Header checksum does not match. Expected 0xAA2A471 and found 0x7421918B (cdbappendonlystorageread.c:849) (seg0 slice1 sdw1:40000 pid=6567) (cdbdisp.c:1525)
Append-Only storage Small Content header: smallcontent_bytes_0_3 0x19011C0F, smallcontent_bytes_4_7 0xCAC01DBA, headerKind = 1, executorBlockKind = 1, rowCount = 71, usingChecksums = true, header checksum 0xAA2A471, block checksum 0x28FAC5BD, dataLength 32342, compressedLength 7610, overallBlockLen 7632
Checksum storage is introduced in GPDB 220.127.116.11. After upgrading to 18.104.22.168 or higher, if the cluster is downgraded to a lower version, the checksum feature does not work and is likely to throw the above error.
Please refer to the documentation for more information: Greenplum Database 4.3.4 Release Notes.
- Verify data is inserted to the Append-Only (AO) tables after downgrading.
- Turn checksum off and run a select on the table to check if it works:
- Check /usr/local to confirm if there are any newer versions of Greenplum (higher than 22.214.171.124) installed.
Check if the cluster has been recently downgraded from 126.96.36.199 or to a lower version. If yes, then upgrade the cluster back to GPDB 188.8.131.52 or higher.
- Upgrading Pivotal Greenplum database (Out of Family): 4.2.x to 4.3.x
- Upgrade Pivotal Greenplum (inside family) from 4.3 to later
- For concepts on Clusters read: GPDB documentation on Cluster
- Internal Reference: JIRA Reference: MPP-25964