AnalyticDB for PostgreSQL exposes a set of instance-level parameters that let you tune query behavior, statement timeouts, and coordinator consistency to match your workload.
Prerequisites
Before you begin, ensure that you have:
An AnalyticDB for PostgreSQL instance
Access to the AnalyticDB for PostgreSQL console
Modify a parameter
Log on to the AnalyticDB for PostgreSQL console.
In the upper-left corner, select a region.
Find the instance you want to manage and click its instance ID.
In the left-side navigation pane, click Parameters.
On the Modifiable Parameters tab, find the parameter you want to change and click the edit icon in the Running Value column.
Enter the new value and click OK.
Click Submit in the upper-right corner of the Modifiable Parameters tab.
In the Modify Parameters dialog box, click OK.
Parameter reference
The following table lists the parameters you can configure.
| Parameter | Type | Default | Valid values | Description |
|---|---|---|---|---|
optimizer | Boolean | on | on, off | Controls which query optimizer the instance uses. on activates the Orca optimizer. off falls back to the Legacy optimizer. For details, see Optimize query performance. |
statement_timeout | Integer | 10800000 | 0–86400000 (ms) | The maximum time a SQL statement can run before the instance stops it. Valid values: 0 to 86400000. Unit: milliseconds. |
rds_master_mode | Enum | single | single, multi_write_ec, multi_write_sc | The consistency mode for the coordinator layer. This parameter is valid only when the instance has multiple coordinator nodes. See the table below for details. |
rds_master_mode values
This parameter is valid only when the instance has multiple coordinator nodes.
| Value | Consistency model | Guarantees |
|---|---|---|
single | Single coordinator | The instance uses one coordinator node. |
multi_write_ec | Session consistency | Within a session: monotonic reads, monotonic writes, reads after writes, and writes after reads. |
multi_write_sc | Global consistency | Full atomicity, consistency, isolation, and durability (ACID) and linearizability across all sessions. |
What's next
To control how much compute resources each query can consume, see Use resource queues to perform workload management.