Performance trace

The performance trace is intended for performance analysis and tuning. This trace includes records of specific events in the system, including events related to distributed data processing. The data can be used for program, resource, user, and subsystem-related tuning.

Begin general-use programming interface information. You can use this information to further identify a suspected problem, or to tune Db2 programs and resources for individual users or for Db2 as a whole.

The performance trace is started when you issue the following command:

-START TRACE(PERFM)

The performance trace defaults to GTF.

Unlike many other trace types, you cannot set a subsystem parameter to specify that Db2 starts the performance trace automatically when Db2 starts.

The following table shows the IFCIDs that are activated for each performance trace class.

Tip: Start of changeIFCID numbers are often presented in Db2 and its documentation with three or four digits and leading zeros. For example, you might find: "IFCID 1," "IFCID 001," or "IFCID 0001." However, you can assume that these references each have the same meaning.End of change
Table 1. Classes for Db2 performance trace
Class Description of class Activated IFCIDs
1 Background events. Class 1 is also activated when you omit the CLASS keyword from the START TRACE command when you start the performance trace. 1, 2, 31, 42, 43, 76, 77, 78, 79, 102, 103, 105, 106 107, 153
2 Subsystem events. Class 2 is also activated when you omit the CLASS keyword from the START TRACE command when you start the performance trace. 3, 68-75, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 106, 174, 175
3 SQL events. Class 3 is also activated when you omit the CLASS keyword from the START TRACE command when you start the performance trace. 22, 53, 55, 58, 59, 60, 61, 62, 63, 64, 65, 66, 92, 95, 96, 97, 106, 112, 173, 177, 233, 237, 250, 272, 273, 325
4 Reads to and writes from the buffer and EDM pools. 6, 7, 8, 9, 10, 29, 30, 105-107, 127, 128, 226, 227, 321, 322, 477
5 Write to log; archive log. 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 104, 106, 114, 115, 116, 117, 118, 119, 120, 228, 229
6 Summary lock information. 20, 44, 45, 105, 106, 107, 172, 196, 213, 214, 218, 337, 396
7 Detailed lock information. 21, 105, 106, 107, 223
8 Data scanning detail. 13-18, 105, 106, 107, 125, 221, 222, 231, 305, 311, 363
9 Sort detail. 26, 28, 95, 96, 106
10 BIND, commands, and utilities detail. 23, 24, 25, 90, 91, 0105, 106, 107, 108, 109, 110, 111, 201, 256
11 Execution unit switch and latch contentions. 46-52, 56, 57, 93, 94, 106, 113
12 Storage manager. 98, 99, 100, 101, 106
13 Edit and validation exits. 11, 12, 19, 105, 106, 107
14 Entry from and exit to an application. 67, 106, 121, 122
15 Installation-defined performance record. 154
16 Distributed processing. 157, 158, 159, 163, 167, 183
17 Claim and drain information. 211, 212, 213, 214, 215, 216
18 Event-based console messages. 197
19 Data set open and close activity. 370, 371
20 Data sharing coherency summary. 249, 251, 256, 257, 261, 262, 267, 268
21 Data sharing coherency detail. 255, 259, 263
22 Authorization exit parameters. 314
23 Language environment runtime diagnostics. 327
24 Stored procedure detail. 380, 499
25-29 Reserved.  
30–32 Available for local use.  

End general-use programming interface information.

Start of change

Performance trace field (IFCID) descriptions

You can find descriptions of trace records in the IFCID flat file (DSNWMSGS). The most current version of DSNWMSGS is available only for clients who have Db2 13 for z/OS® licenses. The information is in a PDF file. To locate this information, see Db2 13 for z/OS IFCID flat file (DSNWMSGS).

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