Dynamic Performance (V$) Views, 155 of 179

V$SQL_SHARED_MEMORY

This view displays information about the cursor shared memory snapshot. Each SQL statement stored in the shared pool has one or more child objects associated with it. Each child object has a number of parts, one of which is the context heap, which holds, among other things, the query plan.

Column Datatype Description

SQL_TEXT

VARCHAR2(1000)

The SQL text of the shared cursor child object that this row is displaying information for

HASH_VALUE

NUMBER

The hash value of the above SQL text in the shared pool

HEAP_DESC

RAW(4)

The address of the descriptor for the context heap of the child cursor described in this row

STRUCTURE

VARCHAR2(16)

If the memory chunk described in this row was allocated using a comment of the form "X : Y", then this is the "X" part of the comment

FUNCTION

VARCHAR2(16)

Similar to the STRUCTURE column, this is the "Y" field of the comment

COMMENT

VARCHAR2(16)

This is the whole comment field that was supplied when this memory chunk was allocated

CHUNK_PTR

RAW(4)

This is the starting address of the allocated memory chunk

CHUNK_SIZE

NUMBER

The amount of memory allocated for this chunk

ALLOC_CLASS

VARCHAR2(8)

Class of memory that this chunk of memory belongs to. It will usually be either FREEABLE or PERMANENT

CHUNK_TYPE

NUMBER

An index into a table of callback functions that tell the server how to recreate this chunk of memory should it need to be removed from the shared pool based on an LRU algorithm

SUBHEAP_DESC

RAW(4)

If the parent heap of this context heap is itself a subheap, then this is the address of the descriptor of the parent heap

Column	Datatype	Description
`SQL_TEXT`	`VARCHAR2(1000)`	The SQL text of the shared cursor child object that this row is displaying information for
`HASH_VALUE`	`NUMBER`	The hash value of the above SQL text in the shared pool
`HEAP_DESC`	`RAW(4)`	The address of the descriptor for the context heap of the child cursor described in this row
`STRUCTURE`	`VARCHAR2(16)`	If the memory chunk described in this row was allocated using a comment of the form "X : Y", then this is the "X" part of the comment
`FUNCTION`	`VARCHAR2(16)`	Similar to the STRUCTURE column, this is the "Y" field of the comment
`COMMENT`	`VARCHAR2(16)`	This is the whole comment field that was supplied when this memory chunk was allocated
`CHUNK_PTR`	`RAW(4)`	This is the starting address of the allocated memory chunk
`CHUNK_SIZE`	`NUMBER`	The amount of memory allocated for this chunk
`ALLOC_CLASS`	`VARCHAR2(8)`	Class of memory that this chunk of memory belongs to. It will usually be either FREEABLE or PERMANENT
`CHUNK_TYPE`	`NUMBER`	An index into a table of callback functions that tell the server how to recreate this chunk of memory should it need to be removed from the shared pool based on an LRU algorithm
`SUBHEAP_DESC`	`RAW(4)`	If the parent heap of this context heap is itself a subheap, then this is the address of the descriptor of the parent heap