Snapshot validation for pessimistic txn #9562
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This pull request was exported from Phabricator. Differential Revision: D31822034 |
ltamasi
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Feb 14, 2022
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Thanks for the PR @riversand963 , LGTM! Maybe change the PR title to "Timestamp-based validation for pessimistic txn" ?
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Thanks @ltamasi for the review! Will update |
Summary: Pull Request resolved: facebook#9562 With per-transaction `read_timestamp_`, it is possible to perform transaction validation after locking a key in addition to sequence-based validation. Specifically, if a transaction has a read_timestamp, then we perform timestamp-based validation as well after the key is locked via `GetForUpdate()`. This is to make sure that no other transaction has modified the key and committed successfully since the read timestamp (but before the locking operation) which represents a consistent view of the database. Reviewed By: ltamasi Differential Revision: D31822034 fbshipit-source-id: 5db143c7fa03860cbb6d0cf4f460ab66bc06fa3d
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This pull request was exported from Phabricator. Differential Revision: D31822034 |
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Summary:
With per-transaction
read_timestamp_, it is possible to perform transaction validation afterlocking a key in addition to sequence-based validation. Specifically, if a transaction has a
read_timestamp, then we perform timestamp-based validation as well after the key is locked
via
GetForUpdate(). This is to make sure that no other transaction has modified the key andcommitted successfully since the read timestamp (but before the locking operation) which
represents a consistent view of the database.
Differential Revision: D31822034