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Row Consistency Read (RCR) UB-Tree Multi-Version Management
Updated on 2024-07-04 GMT+08:00
Row Consistency Read (RCR) UB-Tree Multi-Version Management
- The UB-tree multi-version management adopts the key-based multi-version management. The latest version and historical versions are both on UB-tree.
- To save the space, xmin/xmax is expressed in xid-base + delta. The 64-bit xid-base is stored on pages and the 32-bit delta is stored on tuples. The xid-base on pages also needs to be maintained through additional logic.
- Keys are inserted into or deleted from the UB-tree in the sequence of key + TID. Tuples with the same index column are sorted based on their TIDs as the second keywords. The xmin and xmax are added to the end of the key.
- During index splitting, multi-version information is migrated with key migration.
Parent topic: Index
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