AWS First Steps
New feature

Amazon RDS for SQL Server supports 18 additional SQL trace flags

Amazon RDS for SQL Server now supports 18 new SQL trace flags that can be enabled via database parameter groups, allowing administrators to adjust query optimizer behavior, lock escalation, statistics management, and memory handling.

Amazon RDS for SQL Server now supports 18 new trace flags, enabled via database parameter groups, to modify SQL Server engine behavior. These flags adjust query optimizer cardinality estimates, lock escalation, statistics handling, and memory processing, allowing DBAs to tune performance for workload-specific issues. Supported flags include 647, 652, 1448, 3654, 4138, 4139, 7745, 8285, 8780, 9432, 9481, 9492, 9592, 11024, 11042, 12502, 12618, and 12656, addressing query plan optimization, DDL performance, availability group replication, query store behavior, automatic plan correction, and known engine bugs. As trace flags alter core engine operations, they should be tested in non-production before applying to production instances. Some flags may impact system performance, increasing memory usage or altering query execution plans unexpectedly. These flags are available in all AWS regions where Amazon RDS for SQL Server is supported. To enable, update an RDS parameter group with the desired flags and apply it to your DB instance. For details, see the Amazon RDS for SQL Server user guide.

Why it matters

This update is relevant for Amazon RDS users interested in tuning SQL Server performance or addressing specific issues. It provides more granular control over SQL Server behavior within the managed RDS environment.

Read the original AWS announcement

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