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Merged
davidoliverSP2 merged 5 commits into from
May 16, 2023
Merged

5.x update version to 5.8 #122

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5ca3707
Merge pull request #119 from loveleif/cypher-lost-updates
loveleif Apr 19, 2023
396672c
resolve conflict
loveleif Apr 18, 2023
5eb262a
resolve conflict
loveleif Apr 18, 2023
4d86121
update version to 5.8
AlexicaWright May 16, 2023
2c72cfe
conflicts
AlexicaWright May 16, 2023
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8 changes: 4 additions & 4 deletions antora.yml
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Original file line number Diff line number Diff line change
Expand Up @@ -6,10 +6,10 @@ nav:
- modules/ROOT/content-nav.adoc
asciidoc:
attributes:
neo4j-version: '5.7'
neo4j-version-exact: '5.7.0'
neo4j-buildnumber: '5.7'
java-driver-version: '5.7.0'
neo4j-version: '5.8'
neo4j-version-exact: '5.8.0'
neo4j-buildnumber: '5.8'
java-driver-version: '5.8.0'
neo4j-documentation-branch: 'dev'
page-origin-private: false
neo4j-javadocs-base-uri: "https://neo4j.com/docs/java-reference/5/javadocs"
7 changes: 3 additions & 4 deletions modules/ROOT/pages/transaction-management.adoc
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Expand Up @@ -82,9 +82,7 @@ Due to the limitations of the _read-committed isolation level_, the increments m
If there is a direct dependency, Cypher automatically acquires a write lock before reading.
A direct dependency is when the right-hand side of `SET` has a dependent property read in the expression or the value of a key-value pair in a literal map.

For example, if you run the following query by one hundred concurrent clients, it is very likely not to increment the property `n.prop` to 100, unless a write lock is acquired before reading the property value.
This is because all queries read the value of `n.prop` within their own transaction, and cannot see the incremented value from any other transaction that has not yet been committed.
In the worst case scenario, the final value would be as low as 1 if all threads perform the read before any has committed their transaction.
For example, if you run one of the following queries by one hundred concurrent clients, it will increment the property `n.prop` to 100 because Cypher will automatically acquire a write lock.

.Cypher can acquire a write lock
====
Expand All @@ -108,7 +106,8 @@ SET n += {prop: n.prop + 1}
----
====

Due to the complexity of determining such a dependency in the general case, Cypher does not cover any of the following example cases:
Due to the complexity of determining such a dependency in the general case, Cypher does not cover all cases.
If you run one of the following queries concurrently 100 times, the final value of `n.prop` will most probably be less than 100.

.Complex Cypher
====
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