Updated on 2024-05-07 GMT+08:00

PV_SESSION_MEMORY_CONTEXT

PV_SESSION_MEMORY_CONTEXT displays the memory usage of all sessions based on the MemoryContext node. This view is valid only when enable_thread_pool is set to on.

The memory context TempSmallContextGroup collects information about all memory contexts whose value in the totalsize column is less than 8192 bytes in the current thread, and the number of the collected memory contexts is recorded in the usedsize column. Therefore, the totalsize and freesize columns for TempSmallContextGroup in the view display the corresponding information about all the memory contexts whose value in the totalsize column is less than 8192 bytes in the current thread, and the usedsize column displays the number of these memory contexts.

Table 1 PV_SESSION_MEMORY_CONTEXT columns

Name

Type

Description

sessid

text

Session start time+session ID (string: timestamp.sessionid).

threadid

bigint

ID of the thread bound to a session (-1 if no thread is bound).

contextname

text

Name of the memory context.

level

smallint

Hierarchy of the memory context.

parent

text

Name of the parent memory context.

totalsize

bigint

Total size of the memory context, in bytes.

freesize

bigint

Total size of released memory in the memory context, in bytes.

usedsize

bigint

Size of used memory in the memory context, in bytes. For TempSmallContextGroup, this parameter specifies the number of collected memory contexts.

This view is an O&M view and is used to locate memory problems. Do not query this view concurrently. If you query this view concurrently, the waiting time for new connections increases as the number of concurrent connections increases. As a result, new connections cannot be connected for a long time.