The pdstbegin command outputs to the statistics log file statistical information about a unit located at the server machine with a specified host name. When output of statistical information is to be stopped, the pdstend command must be executed.
The statistical information is output to the statistics log file named pdstj1 or pdstj2 at each host.
The obtained statistical information can be read by the statistics analysis utility. For details about the statistics analysis utility, see Chapter 14. Statistics Analysis Utility (pdstedit).
HiRDB administrator
pdstbegin [-k statistical-information-type[,statistical-information-type]...] |
pdstbegin [-k statistical-information-type[,statistical-information-type]...] |
Specifies the type of statistical information to be output:
When system activity statistical information (-k sys specified) is to be output to the statistics log file, specifies in minutes the interval at which the information is to be output.
Specifies the identifier of the unit or the name of the host for which statistical information is to be output. If this option is omitted, statistical information for the entire HiRDB system is output to the statistics log file.
Specifies the servers for which statistical information is to be output. When this option is omitted, the statistical information to be output depends on the server type. For details about the statistical information that is output, see Table 2-16 Relationship between statistical information output and the -s option specification: HiRDB/Single Server or Table 2-17 Relationship between statistical information output and the -s option specification: HiRDB/Parallel Server.
Specifies that information about thread-to-thread lock-release wait time is to be collected as statistical information. The thread-to-thread lock-release wait time is the time required to acquire a thread-to-thread lock since a thread-to-thread lock request was placed in wait status.
You can collect information about thread-to-thread lock-release wait time as part of the following statistical information:
To collect information about thread-to-thread lock-release wait time, the system activity statistical information must also be collected. Therefore, if you are not collecting the system activity statistical information, collect it.
To collect more accurate information, execute the pdstjsync command immediately before or after you execute this command. For details, see 2-93 pdstjsync (Apply statistics log buffer to statistics log file).
To check the collection status of statistical information on the thread-to-thread lock-release wait time, execute the pdls -d stj command. For details, see 2-66 pdls [-d stj] (Display whether statistical data output type by unit and server is specified).
The following describes the conditions under which the statistical information on the thread-to-thread lock-release wait time can be collected for each statistical information type.
System activity statistical information (sys)
The following figure shows the period for which the system activity statistical information and the statistical information on the thread-to-thread lock-release wait time can be collected.
Figure 2-6 Period for which the statistical information on the thread-to-thread lock-release wait time can be collected (sys)
The period for which statistical information on the thread-to-thread lock-release wait time can be collected is from t3 to t4.
UAP statistical information (uap)
The following figure shows the period for which the UAP statistical information and the statistical information on the thread-to-thread lock-release wait time can be collected.
Figure 2-7 Period for which the statistical information on the thread-to-thread lock-release wait time can be collected (uap)
You can collect statistical information on the thread-to-thread lock-release wait time for UAPs that are started between the time the pdstbegin -w command is executed and the time the pdstend -w command is executed.
Global buffer pool statistical information (buf)
The following figure shows the period for which the global buffer pool statistical information and the statistical information on the thread-to-thread lock-release wait time can be collected.
Figure 2-8 Period for which the statistical information on the thread-to-thread lock-release wait time can be collected (buf)
After the pdstbegin -w command is executed, the period for which accurate statistical information on the thread-to-thread lock-release wait time can be collected is from synchronization point s2 that falls immediately after execution of the pdstbegin -w command to synchronization point s4 that falls immediately after execution of the pdstend -w command. In this example, the pdstend -w command is executed during transaction D, but the statistical information on the thread-to-thread lock-release wait time is collected until the transaction is completed.
If the unit contains a server that is not collecting statistical information on the thread-to-thread lock-release wait time, a value displayed as the result of editing the system activity statistical information for each unit will be smaller than the actual value. Therefore, if you limit the servers that will collect the system activity statistical information, evaluate the statistical information from the editing results for each server.
Table 2-16 Relationship between statistical information output and the -s option specification: HiRDB/Single Server
Types of statistical information | Servers specified with -s option (Single Server) |
---|---|
sys | Y |
uap | Y |
sql | Y |
sqh | Y |
buf | Y |
fil | Y |
dfw | Y |
idx | Y |
sop | Y |
dop | Y |
pcd | Y |
obj | -- |
fsv | -- |
hba | -- |
Table 2-17 Relationship between statistical information output and the -s option specification: HiRDB/Parallel Server
Types of statistical information | Servers specified with -s option | ||
---|---|---|---|
FES | DS | BES | |
sys | Y | Y | Y |
uap | Y | -- | -- |
sql | Y | -- | -- |
sqh | Y | -- | -- |
buf | -- | Y | Y |
fil | -- | Y | Y |
dfw | -- | Y | Y |
idx | -- | Y | Y |
sop | Y | -- | -- |
dop | Y | -- | -- |
pcd | Y | Y | Y |
obj | -- | Y | Y |
fsv | -- | -- | Y |
hba | -- | -- | Y |
Figure 2-9 Relationship between output of statistical information and entry of the pdstbegin and pdstend commands
Server type | Server status | Target |
---|---|---|
Host BES | Executing | Y |
Standby | N | |
Guest BES | Executing | Y |
Acceptable status | N |