querybufferstats系统表描述

描述

A pseudo table generated to show queries that have used significant amounts of memory. In NuoDB 3.4 this is currently limited to sorting operations (those running queries that use the ORDER BY clause). Support for additional operations will be added in future releases of NuoDB.

By default, the ten queries with the highest memory usage in compatible processing modules are stored in the QUERYBUFFERSTATS table. The number of queries listed is configurable using the MAX_QUERY_COUNT system property. For more information on using MAX_QUERY_COUNT, see SQL系统属性.

领域

场地 类型 描述

Sqlstring.

细绳

执行时需要内存的SQL语句。

用户

细绳

用于数据库连接的SQL用户。

架构

细绳

调用查询时连接的当前SQL模式。

参数

细绳

表示查询中指定的参数的字符串。表示每个参数的字符串是格式:

n/type/value

在哪里:

n 是从0开始的参数的数量。
type 是变量的类型,即整数,字符串等。
value 值是否传递给参数。

每个参数字符串由空格分隔。例如:

numparam.

参数

\ -----------------

\ -------------------------

2

0 / string /'hello'1 / Integer / 3

nodeid.

big

一个唯一标识符,指定了哪个te查询’S客户端已连接到。

data_buffering_mb.

big

The peak amount of memory buffering required to process this query. For more information, refer to DISKSPILL_MEMORY_THRESHOLD in SQL系统属性.

时间戳

细绳

查询开始时的时间戳。

索引

Primary Index: VERSIONS..PRIMARY_KEY on field: PROPERTY