• group_concat_max_len

    Command-Line Format --group-concat-max-len=#
    System Variable group_concat_max_len
    Scope Global, Session
    Dynamic Yes
    SET_VAR Hint Applies Yes
    Type Integer
    Default Value 1024
    Minimum Value 4
    Maximum Value (64-bit platforms) 18446744073709551615
    Maximum Value (32-bit platforms) 4294967295

    The maximum permitted result length in bytes for the GROUP_CONCAT() function. The default is 1024.

  • have_compress

    YES if the zlib compression library is available to the server, NO if not. If not, the COMPRESS() and UNCOMPRESS() functions cannot be used.

  • have_dynamic_loading

    YES if mysqld supports dynamic loading of plugins, NO if not. If the value is NO, you cannot use options such as --plugin-load to load plugins at server startup, or the INSTALL PLUGIN statement to load plugins at runtime.

  • have_geometry

    YES if the server supports spatial data types, NO if not.

  • have_openssl

    This variable is a synonym for have_ssl.

    As of MySQL 8.0.26, have_openssl is deprecated and subject to removal in a future MySQL version. For information about TLS properties of MySQL connection interfaces, use the tls_channel_status table.

  • innodb_flush_log_at_trx_commit=1.

  • System variables that are true or false can be enabled at server startup by naming them, or disabled by using a --skip- prefix. For example, to enable or disable the InnoDB adaptive hash index, you can use --innodb-adaptive-hash-index or --skip-innodb-adaptive-hash-index on the command line, or innodb_adaptive_hash_index or skip_innodb_adaptive_hash_index in an option file.

  • innodb_buffer_pool_chunk_size

    Command-Line Format --innodb-buffer-pool-chunk-size=#
    System Variable innodb_buffer_pool_chunk_size
    Scope Global
    Dynamic No
    SET_VAR Hint Applies No
    Type Integer
    Default Value 134217728
    Minimum Value 1048576
    Maximum Value innodb_buffer_pool_size / innodb_buffer_pool_instances
    Unit bytes

    innodb_buffer_pool_chunk_size defines the chunk size for InnoDB buffer pool resizing operations.

    To avoid copying all buffer pool pages during resizing operations, the operation is performed in chunks. By default, innodb_buffer_pool_chunk_size is 128MB (134217728 bytes). The number of pages contained in a chunk depends on the value of innodb_page_size. innodb_buffer_pool_chunk_size can be increased or decreased in units of 1MB (1048576 bytes).

    The following conditions apply when altering the innodb_buffer_pool_chunk_size value:

    Important

    Care should be taken when changing innodb_buffer_pool_chunk_size, as changing this value can automatically increase the size of the buffer pool. Before changing innodb_buffer_pool_chunk_size, calculate its effect on innodb_buffer_pool_size to ensure that the resulting buffer pool size is acceptable.

    To avoid potential performance issues, the number of chunks (innodb_buffer_pool_size / innodb_buffer_pool_chunk_size) should not exceed 1000.

    The innodb_buffer_pool_size variable is dynamic, which permits resizing the buffer pool while the server is online. However, the buffer pool size must be equal to or a multiple of innodb_buffer_pool_chunk_size * innodb_buffer_pool_instances, and changing either of those variable settings requires restarting the server.

    See Section 17.8.3.1, “Configuring InnoDB Buffer Pool Size” for more information.

  • innodb_buffer_pool_chunk_size

    Command-Line Format --innodb-buffer-pool-chunk-size=#
    System Variable innodb_buffer_pool_chunk_size
    Scope Global
    Dynamic No
    SET_VAR Hint Applies No
    Type Integer
    Default Value 134217728
    Minimum Value 1048576
    Maximum Value innodb_buffer_pool_size / innodb_buffer_pool_instances
    Unit bytes

    innodb_buffer_pool_chunk_size defines the chunk size for InnoDB buffer pool resizing operations.

    To avoid copying all buffer pool pages during resizing operations, the operation is performed in chunks. By default, innodb_buffer_pool_chunk_size is 128MB (134217728 bytes). The number of pages contained in a chunk depends on the value of innodb_page_size. innodb_buffer_pool_chunk_size can be increased or decreased in units of 1MB (1048576 bytes).

    The following conditions apply when altering the innodb_buffer_pool_chunk_size value:

    Important

    Care should be taken when changing innodb_buffer_pool_chunk_size, as changing this value can automatically increase the size of the buffer pool. Before changing innodb_buffer_pool_chunk_size, calculate its effect on innodb_buffer_pool_size to ensure that the resulting buffer pool size is acceptable.

    To avoid potential performance issues, the number of chunks (innodb_buffer_pool_size / innodb_buffer_pool_chunk_size) should not exceed 1000.

    The innodb_buffer_pool_size variable is dynamic, which permits resizing the buffer pool while the server is online. However, the buffer pool size must be equal to or a multiple of innodb_buffer_pool_chunk_size * innodb_buffer_pool_instances, and changing either of those variable settings requires restarting the server.

    See Section 17.8.3.1, “Configuring InnoDB Buffer Pool Size” for more information.