Supported Type | Description | Sample |
Variable | DBinitMemory: Memory size of instance specification, which is an integer. For example, if the memory size of the instance specification is 4,000 MB, the value of DBinitMemory will be 4000.DBInitCpu: Number of CPU cores of instance specification, which is an integer. Note that the value of the innodb_buffer_pool_size parameter in TencentDB for MySQL must be between 50% and 90% of the memory size. If the configured value is above 90% or below 50%, it will be automatically configured to 90% or 50% respectively. | {DBinitMemory * 786432}: DBinitMemory * percentage (75% by default) * 1024 * 1024 (unit conversion). |
Operator | Formula syntax: It should be enclosed in braces ({}). Division operator (/): It divides the dividend by the divisor and returns an integer quotient. If the calculation result is a decimal number, only the integer part will be retained. Decimal numbers are not supported; for example, {MIN(DBInitMemory/4+500,1000000)} instead of {MIN(DBInitMemory\\*0.25+500,1000000)} is supported.Multiplication operator (*): It multiplies two numbers and returns an integer product. If the calculation result is a decimal number, only the integer part will be retained. Decimal number calculation is not supported. | - |
Function | MAX(): It returns the greatest value in an integer or parameter formula list. MIN(): It returns the smallest value in an integer or parameter formula list. | {MAX(DBInitCpu/2,4)} |
Changed Parameter | Default Template | High-Performance Template | High-Stability Template |
innodb_read_io_threads | 12 | {MAX(DBInitCpu/2,4)} | {MAX(DBInitCpu/2,4)} |
innodb_write_io_threads | 12 | {MAX(DBInitCpu/2,4)} | {MAX(DBInitCpu/2,4)} |
max_connections | 800 | {MIN(DBInitMemory/4+500,100000)} | {MIN(DBInitMemory/4+500,100000)} |
table_definition_cache | 768 | {MAX(DBInitMemory*512/1000,2048)} | {MAX(DBInitMemory*512/1000,2048)} |
table_open_cache | 2000 | {MAX(DBInitMemory*512/1000,2048)} | {MAX(DBInitMemory*512/1000,2048)} |
table_open_cache_instances | 16 | {MIN(DBInitMemory/1000,16)} | {MIN(DBInitMemory/1000,16)} |
innodb_disable_sort_file_cache | OFF | OFF | ON |
innodb_log_compressed_pages | ON | OFF | ON |
innodb_print_all_deadlocks | OFF | OFF | ON |
sync_binlog | 0 | 1000 | 1 |
thread_handling | one-thread-per-connection | pool-of-threads | one-thread-per-connection |
innodb_flush_redo_using_fdatasync | FALSE | TRUE | FALSE |
innodb_fast_ahi_cleanup_for_drop_table | FALSE | TRUE | FALSE |
innodb_adaptive_hash_index | FALSE | TRUE | FALSE |
innodb_table_drop_mode | SYNC_DROP | ASYNC_DROP | SYNC_DROP |
innodb_flush_log_at_trx_commit | 2 | 2 | 1 |
Parameter | TencentDB for MySQL 5.6 | TencentDB for MySQL 5.7 | TencentDB for MySQL 8.0 |
character_set_client | - | ✓ | - |
default_password_lifetime | - | ✓ | ✓ |
innodb_alter_table_default_algorithm | - | ✓ | - |
innodb_async_truncate_size | - | ✓ | ✓ |
innodb_async_truncate_work_enabled | - | ✓ | - |
innodb_buffer_pool_instances | ✓ | ✓ | ✓ |
innodb_buffer_pool_size | ✓ | ✓ | ✓ |
innodb_default_row_format | - | ✓ | ✓ |
innodb_fast_ahi_cleanup_for_drop_table | - | - | ✓ |
innodb_flush_redo_using_fdatasync | - | ✓ | ✓ |
innodb_page_cleaners | - | ✓ | ✓ |
innodb_table_drop_mode | - | - | ✓ |
innodb_temp_tablespace_fast_cleanup | - | - | ✓ |
internal_tmp_mem_storage_engine | - | - | ✓ |
slave_net_timeout | ✓ | ✓ | - |
slave_parallel_type | ✓ | - | - |
slave_parallel_workers | ✓ | ✓ | ✓ |
sort_buffer_size | ✓ | - | - |
temptable_use_mmap | - | - | ✓ |
thread_handling | ✓ | ✓ | ✓ |
thread_handling_switch_mode | - | - | ✓ |
thread_pool_oversubscribe | ✓ | ✓ | ✓ |
thread_pool_size | - | ✓ | ✓ |
tx_isolation | - | ✓ | ✓ |
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