23ai New Feature - Lock-Free Reservations (Doc ID 3071650.1)

Last updated on FEBRUARY 16, 2025

Applies to:

Purpose

The intent of this document is to introduce 23ai New Feature Lock-Free Reservations.

Many transactions concurrently accessing numeric data is high, and often this data is identified as a "hot" resource because applications continuously, and repeatedly, read or update such data. In previous releases, when a column value of a row is updated by adding or subtracting from it, all other updates to that row are blocked until the transaction is committed. By avoiding the traditional locking mechanism during updates, Lock-Free reservation allows you to greatly improve on the user experience with reduced blocking in the presence of frequent concurrent updates to numeric data.

Lock-Free Reservation allows multiple concurrent updates, on a numeric column value, to proceed without being blocked by uncommitted updates when adding or subtracting from the column value.With Lock-Free reservation, you could instead allow transactions to concurrently add or subtract from the same reservable column without blocking each other by specifying the conditions for which the updates may proceed. This is accomplished by specifying that the numeric column is a RESERVABLE column and by creating a CHECK constraint for the column to ensure a sufficient quantity of the item is available before allowing the transaction to perform the reservation.

Please also refer to the following online documentation for more details:

Oracle Database Release 23
Oracle Database New Features
Database Architecture
Lock-Free Reservations

Scope

The article will be useful for Oracle Dba's, developers and Support Analysts.

Details

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