SELECT FILE_ID, FILE_NAME, FILE_TYPE, TABLESPACE_NAME, FREE_EXTENTS, TOTAL_EXTENTS, EXTENT_SIZE, INITIAL_SIZE, MAXIMUM_SIZE, AUTOEXTEND_SIZE, DATA_FREE, STATUS ENGINE FROM INFORMATION_SCHEMA.FILES \G 1. 2:INNODB_SYS_DATAFILES 我们来重新查一下这个记录信息: 很容易看出来这张表就是记录的表的...
翻译下来,该字段作用为:在mysql5.0.7及其以上的版本,mysql驱动是否通过DatabaseMetaData去获取INFORMATION_SCHEMA信息。 8.0之后的版本 Connector/J now takes advantage of the MySQL Server 8.0 data dictionary by making the connection property useInformationSchema true by default; this makes Connector/J, by def...
详细表述了某个表属于哪个schema,表类型,表引擎,创建时间,等等信息。是show tables from schemaname的结果取之此表。 COLUMNS表 ---COLUMNS表提供了表中的列信息。详细表述了某张表的所有列以及每个列的信息。是show columns from schemaname.tablename的结果取之此表。 STATISTICS表 ---STATISTICS表提供了关于表索...
google找了半天,总算知道原因: Connector/J 5.0.0以后的版本有一个名为useInformationSchema的数据库连接参数, 在默认连接参数情况下,useInformationSchema=false,导致Connection.getMetaData()方法返回的DatabaseMetaData 对象是com.mysql.jdbc.DatabaseMetaData,而不是com.mysql.jdbc。DatabaseMetaDataUsingInfoSchema,Databa...
Using the Information Schema Querying the metadata on a data source is the easiest way to determine the makeup of a table if you don’t have an understanding of it already.Microsoft SQL Serverprovides an information schema view as one of several methods for obtaining this metadata. As their ...
| information_schema | | mysql | | performance_schema | | peter | | school | | sys | +---+ 6 rows in set (0.04 sec) mysql> use school; // 选择使用数据库 Reading table information for completion of table and column names You can turn off this feature...
在下文中一共展示了ConnectionProperties.setUseInformationSchema方法的1个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的Java代码示例。 示例1: setUseInformationSchema ▲点赞 2▼ importcom.mysql.jdbc.ConnectionProperties;//导入方法依赖的pa...
查看crash 日志我们可以看到 crash 时 MySQL 最后执行的是一条select * from information_schema.processlist命令,从 crash 的堆栈信息来看,基本就是执行一个普通的 sql 触发了 libstdc 这个库的异常,导致数据库发出信号直接 abort MySQL ,个人不太懂代码。从错误信息中basic_string::_S_construct null not valid的...
SIGNAL locked WAIT_FOR view_recreated'; --send CALL p1() --echo # Connection 2 connection con2; SET DEBUG_SYNC= 'now WAIT_FOR locked'; --echo # ... then drop and recreate the view DROP VIEW v1; CREATE VIEW v1 AS SELECT engine FROM information_schema.engines; --echo # Now ...
However, the current implementation of INFORMATION_SCHEMA tables does not take advantage of the relational structure of the system tables even for the mentioned subset: the data is copied first into an internal temporary table, and only then the query is executed against the temporary table. ...