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Updated on 2025-06-26 GMT+08:00

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Viewing Suggestions on TaurusDB Parameter Tuning

Parameters are key configuration items in a database system. Improper parameter settings may adversely affect database performance. This section describes some important parameters for your reference. For details, see MySQL official website.

For details on how to modify TaurusDB parameters on the console, see Modifying Parameters of a DB Instance.

Performance Parameters

innodb_flush_log_at_trx_commit

Default value: 1
Function: Controls the balance between strict ACID compliance for commit operations and higher performance.
Parameter setting:
- 1: InnoDB writes data in the log buffer to log files and then flushes the data to distributed storage at each transaction commit. The ACID properties of transactions are ensured.
- 0: InnoDB writes data in the log buffer to log files and then flushes the data to distributed storage every second.
- 2: InnoDB writes data in the log buffer to the file system cache at each transaction commit, and flushes the data to distributed storage every second.
Impact: If this parameter is not set to 1, data security is not guaranteed. One second of transactions can be lost in a crash.
Recommended value for PoC: 0. This setting can significantly improve write performance in low concurrency scenarios.

rds_global_sql_log_bin

In 2.0.42.230601 and earlier versions, binlog is enabled by default. To enable or disable it, you need to configure the log-bin parameter and then reboot your instance.
In 2.0.45.230900 and later versions, binlog is disabled by default. To enable or disable it, you need to configure the rds_global_sql_log_bin parameter.

Default value: OFF
Function: Controls whether to enable or disable binlog. TaurusDB uses a shared storage architecture. The primary node and read replicas in a DB instance do not depend on binlogs for data synchronization. You can disable binlog as required.
Parameter setting:
- OFF: Binlog is disabled. The setting is applied to both existing and new connections without an instance reboot.
- ON: Binlog is enabled. The setting is applied to both existing and new connections without an instance reboot.
Impact: Enabling or disabling it does not affect your instance.
Recommended value for PoC: OFF. This setting can improve write performance.

rds_plan_cache

This feature can be enabled in 2.0.51.240300 and later versions.
rds_plan_cache uses the memory allocated by the stmt mem memory area instead of the innnodb_buffer memory.
rds_plan_cache_allow_change_ratio: Table data change rate caused by query operations such as DML. If the change rate exceeds this parameter value, plan caches become invalid. If this parameter is set to 0, plan caches are not affected by the table data change ratio. They are always valid.

Default value: OFF
Function: Controls whether to cache the execution plan of a PREPARE statement.
Parameter setting: If rds_plan_cache is set to ON, the execution plan of the PREPARE statement is cached. The cached execution plan can be reused in the next execution, improving query performance.
Impact: The query performance of the PREPARE statement is greatly improved, and the select_random_ranges test model of sysbench is significantly enhanced.
Recommended value for PoC: ON. This setting can improve query performance.

Modifying Compatibility Parameters

rds_compatibility_mode

Default value: The default value is empty.
Function: Controls the compatibility with features such as functions and syntax specific to earlier versions of the community.

Parameter setting: Table 1 lists the values.

**Table 1** **rds_compatibility_mode** description
Value	Description
ALLOW_DATE_COMPARE_AS_STRING	Controls whether to allow the DATETIME, DATE, or TIMESTAMP type to be compared with a character string that failed to be converted to the DATETIME, DATE, or TIMESTAMP type.
ALLOW_DATETIME_TZ_MONTH_DAY_ZERO	Controls whether to insert DATETIME values with time zones and the month and day being 0. If this option is enabled, the system processes these values according to the behavior of versions earlier than MySQL 8.0.19. That is, the system truncates the time zone information and stores only the date and time.
ALLOW_UNSECURE_CIPHER_FUNC	Controls whether to be compatible with some encryption functions of MySQL 5.7, such as ENCODE(), DECODE(), ENCRYPT(), DES_ENCRYPT(), and DES_DECRYPT().
ALLOW_RENAMED_DEPRECATED_FUNC	Controls whether to be compatible with deprecated geographic information system (GIS) functions in MySQL 5.7. GIS functions have been renamed since MySQL 5.7.
ALLOW_BACKSLASH_N_AS_NULL	Controls whether to allow the \N keyword to be parsed as NULL. This keyword has been deprecated in MySQL 8.0.1. Example: CREATE TABLE n1(a int DEFAULT \N);
ALLOW_EARLIER_ROWID_FILESORT	If this mode is enabled, the max_length_for_sort_data criterion will be re-introduced to select a file sorting mode, and additional columns will not be loaded when the rowid sorting mode is used.
ALLOW_GROUP_BY_IMPLICIT_SORTING	Controls whether to be compatible with the implicit sorting of the GROUP BY clause in MySQL 5.7.
ALLOW_GROUP_BY_ASC_DESC	Controls whether to be compatible with the explicit sorting of the GROUP BY clause in MySQL 5.7: GROUP BY column [ASC \| DESC].