AWS redshift documentation change
Summary
Restructured transaction isolation examples, added new sections for snapshot isolation concurrency behavior
Security assessment
Changes focus on transaction isolation levels and concurrency behavior without mentioning security vulnerabilities or security features. Updates are operational documentation about database transaction handling.
Diff
diff --git a/redshift/latest/dg/r_Serializable_isolation_example.md index 72cc2b31f..eb595e72b 100644 --- a/redshift/latest/dg/r_Serializable_isolation_example.md +++ b/redshift/latest/dg/r_Serializable_isolation_example.md @@ -5 +5 @@ -Concurrent COPY operations into the same tableConcurrent DELETE operations from the same tableConcurrent transactions with a mixture of read and write operations +Concurrent write examples with serializable isolation Concurrent write examples with snapshot isolation @@ -11 +11,3 @@ The following pseudo-code examples demonstrate how transactions either proceed o -## Concurrent COPY operations into the same table +## Concurrent write examples with serializable isolation + +### Concurrent COPY operations into the same table with serializable isolation @@ -32 +34 @@ The same behavior would occur if one or both transactions contained an INSERT co -## Concurrent DELETE operations from the same table +### Concurrent DELETE operations from the same table with serializable isolation @@ -53 +55 @@ The same behavior would occur if one or both transactions contained an UPDATE co -## Concurrent transactions with a mixture of read and write operations +### Concurrent transactions with a mixture of read and write operations with serializable isolation @@ -78,0 +81,29 @@ The second transaction will succeed because it must wait for the first to comple +## Concurrent write examples with snapshot isolation + +### Concurrent COPY operations into the same table with snapshot isolation + +Transaction 1 copies rows into the LISTING table: + + + begin; + copy listing from ...; + end; + +Transaction 2 starts concurrently in a separate session and attempts to copy more rows into the LISTING table. Transaction 2 can progress simultaneously until either transaction needs to write data to the target table `listing`, at which point they will run sequentially. + + + begin; + //When the COPY statement from T1 needs to write data to the table, the COPY statement from T2 waits. + copy listing from ...; + end; + +The same behavior would occur if one or both transactions contained an INSERT command instead of a COPY command. + +### Concurrent DELETE operations from the same table with snapshot isolation + +Concurrent DELETE or UPDATE operations from the same table with snapshot isolation run the same as operations run with serializable isolation. + +### Concurrent transactions with a mixture of read and write operations with snapshot isolation + +Concurrent transactions that are run with mixes of operations with snapshot isolation run the same as transactions with mixes of operations that are run with serializable isolation. +