System Monitor Guide and Reference

Snapshot Output

A snapshot monitor returns its data as a self-describing data stream. Figure 7 shows the structure of the data stream and Table 2 provides some examples of the logical data groups and data elements that may be returned.

Note:

In the examples and tables descriptive names are used for the identifiers. These names are prefixed by SQLM_ELM_ in the actual data stream. For example, collected would appear as SQLM_ELM_COLLECTED in the snapshot monitor output. Types are prefixed with SQLM_TYPE_ in the actual data stream. For example, headers appear as SQLM_TYPE_HEADER in the data stream.

Figure 7. Snapshot Monitor Data Stream

1. Each logical data group begins with a header that indicates its size and name.
2. Size in the collected header returns the total size of the snapshot.
3. The size element in other headers indicates the size of all the data in that logical data group, including any subordinate groupings.
4. Data element information follows its logical data group header and is also self-describing.

Table 2. Sample Snapshot Data Stream

Logical Data Group			Data Stream	Description
collected			1000 header collected	Size of the entire snapshot buffer (in bytes). Indicates the start of a logical data group. Name of the logical data group.
			4 u32bit server_db2_type sqlf_nt_server	Size of the data stored in this data element. Data element type - unsigned 32 bit numeric. The name of the data element collected. The collected value for this element.
			2 u16bit node_number 3	Size of the data stored in this data element. Data element type - unsigned 16 bit numeric. The name of the data element collected. The collected value for this element.
	db2		200 header db2	Size of the db2 level portion of data in the snapshot. Indicates the start of a logical data group. Name of the logical data group.
			4 u32bit sort_heap_allocated 16	Size of the data stored in this data element. Data element type - unsigned 32 bit numeric. The name of the data element collected. The collected value for this element.
			4 u32bit local_cons 3	Size of the data stored in this data element. Data element type - unsigned 32 bit numeric. The name of the data element collected. The collected value for this element.
	appl		100 header appl	Size of the appl element data in the snapshot. Indicates the start of a logical data group. Name of the logical data group.
			4 u32bit locks_held 3	Size of the data stored in this data element. Data element type - unsigned 32 bit numeric. The name of the data element collected. The collected value for this element.
		agent	50 header agent	Size of the agent portion of the appl structure. Indicates the start of a logical data group. Name of the logical data group.
			4 u32bit agent_pid 12	Size of the data stored in this data element. Data element type - 32 bit numeric. The name of the data element collected. The collected value for this element.