Help Center/ GaussDB/ Feature Guide(Centralized_8.x)/ Storage Engine/ Ustore/ Storage Format/ UB-Tree/ PCR UB-Tree/ Adding, Deleting, Modifying, and Querying PCR UB-Tree
Updated on 2024-06-07 GMT+08:00
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Adding, Deleting, Modifying, and Querying PCR UB-Tree

  • Insert: The operation is basically the same as that of RCR UB-tree. The difference is that a TD needs to be allocated and undo logs need to be written before insertion.
  • Delete: The operation is basically the same as that of RCR UB-tree. The difference is that a TD needs to be allocated and undo logs need to be written before deletion.
  • Update: The operation is the same as that of RCR UB-tree. That is, the operation is converted into a Delete operation and an Insert operation.
  • Scan: The operation is basically the same as that of RCR UB-tree. The difference is that the query operation needs to copy a CR page and roll back the CR page to the state visible to the snapshot. In this way, the tuples on the entire page are visible to the snapshot.
Parent topic: PCR UB-Tree