倒数第二段，MySQL has no limit on the number of tables. The underlying file systemmay have a limit on the number of files that represent tables.Individual storage engines may impose engine-specific constraints.InnoDB permits up to 4 billion tables.告诉你，表的建立是有限制的，如果使用InnoDB 存储...
concat( round( ( data_length+index_length )/(1024*1024*1024),6),' G')AS'Total'FROMinformation_schema.TABLES WWHEREtable_schemaLIKE'database name'; 3、查看表空间 # 单位GBSELECTconcat( round(sum( data_length )/(1024*1024*1024),6),'GB')AS'Total Data Size'FROMinformation_schema.TABLESW...
key_buffer_size = 16M #索引缓存区大小,一般设置物理内存的30-40% read_buffer_size = 128K #读操作缓冲区大小,推荐设置16M或32M query_cache_type = ON #打开查询缓存功能 query_cache_limit = 1M #查询缓存限制,只有1M以下查询结果才会被缓存,以免结果数据较大把缓存池覆盖 query_cache_size = 16M #查看...
–mysql-ignore-errors=[LIST,…] list of errors to ignore, or “all” [1213,1020,1205] #要忽略或“全部”的错误列表 --mysql-dry-run[=on|off] Dry run, pretend that all MySQL client API calls are successful without executing them [off] #模拟运行,假设所有的MySQL客户端API调用都是成功的,...
TABLES 提供有关数据库中表的信息 TABLE_CONSTRAINTS 描述了哪些表具有约束 TRIGGERS 提供有关触发器的信息 VIEWS 提供有关数据库中的视图的信息 VIEW_ROUTINE_USAGE (从MySQL 8.0.13开始可用)提供对视图定义中使用的存储函数的信息的访问。该表未列出有关定义中使用的内置SQL函数或用户定义函数(UDF)的信息。 VIEW...
When decreasing the size of the buffer pool, the resizing operation: Defragments the buffer pool and withdraws (frees) pages Removes pages in chunks (chunk size is defined by innodb_buffer_pool_chunk_size) Converts hash tables, lists, and pointers to use new addresses in memory Of th...
or the list is too long select * from tmp_sel_arg1 where kp1 not in (1, 2, 3, 4, 5) (gdb) my st tree $b0 (SEL_TREE *) 0x7f7cf040acd0 [type=SEL_TREE::KEY,keys.m_size=1] `--$b1 (SEL_ROOT *) 0x7f7cf040adc8 [type=SEL_ROOT::Type::KEY_RANGE, use_count=1, ...
2.3 设置batchSize 在更新list之前,我们可以使用cursor对象的arraysize属性来控制每次从数据库中获取的数据行数。默认情况下,arraysize的值为 1,即每次从数据库中获取一行数据。你可以将其设置为较大的值来提高执行效率。 # 创建游标cursor=cnx.cursor()# 设置batchSize为100cursor.arraysize=100 ...
8之前，InnoDB存储引擎严格的保证MTR写入Redo Log Buffer的顺序是按照LSN递增的顺序，以及flush list中的...
The size of the index file pointer, in bytes. It is usually 1, 2, or 3 bytes. Most tables manage with 2 bytes, but this is calculated automatically by MySQL. It is always a block address. Max datafile length How long the table data file can become, in bytes. ...