| Command-Line Format | --group-concat-max-len=# | 
|---|---|
| System Variable | group_concat_max_len | 
| Scope | Global, Session | 
| Dynamic | Yes | 
| SET_VARHint 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.
    
        YES if the zlib
        compression library is available to the server,
        NO if not. If not, the
        COMPRESS()
        and
        UNCOMPRESS() functions cannot
        be used.
    
        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.
    
        YES if the server supports spatial data
        types, NO if not.
    
        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.
    
        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.
    
| Command-Line Format | --innodb-buffer-pool-chunk-size=# | 
|---|---|
| System Variable | innodb_buffer_pool_chunk_size | 
| Scope | Global | 
| Dynamic | No | 
| SET_VARHint 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:
    
                    If 
        innodb_buffer_pool_chunk_size *
                    innodb_buffer_pool_instances
                    is larger than the current buffer pool size when the
                    buffer pool is initialized,
                    innodb_buffer_pool_chunk_size
                    is truncated to
                    innodb_buffer_pool_size /
                    innodb_buffer_pool_instances.
                
                    Buffer pool size must always be equal to or a multiple of
                    innodb_buffer_pool_chunk_size
                    *
                    innodb_buffer_pool_instances.
                    If you alter
                    innodb_buffer_pool_chunk_size,
                    innodb_buffer_pool_size
                    is automatically rounded to a value that is equal to or a
                    multiple of
                    innodb_buffer_pool_chunk_size
                    *
                    innodb_buffer_pool_instances.
                    The adjustment occurs when the buffer pool is initialized.
                
            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.
| Command-Line Format | --innodb-buffer-pool-chunk-size=# | 
|---|---|
| System Variable | innodb_buffer_pool_chunk_size | 
| Scope | Global | 
| Dynamic | No | 
| SET_VARHint 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:
    
                    If 
        innodb_buffer_pool_chunk_size *
                    innodb_buffer_pool_instances
                    is larger than the current buffer pool size when the
                    buffer pool is initialized,
                    innodb_buffer_pool_chunk_size
                    is truncated to
                    innodb_buffer_pool_size /
                    innodb_buffer_pool_instances.
                
                    Buffer pool size must always be equal to or a multiple of
                    innodb_buffer_pool_chunk_size
                    *
                    innodb_buffer_pool_instances.
                    If you alter
                    innodb_buffer_pool_chunk_size,
                    innodb_buffer_pool_size
                    is automatically rounded to a value that is equal to or a
                    multiple of
                    innodb_buffer_pool_chunk_size
                    *
                    innodb_buffer_pool_instances.
                    The adjustment occurs when the buffer pool is initialized.
                
            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.