Measures reported by ProLatchTest
A latch is a “lightweight lock”. A latch acts like a lock, in that its purpose is to prevent data from changing unexpectedly. Just like a lock, a latch can prevent the Progress database server from accessing rows in a database, which can hurt performance. Because of this, latch wait time must be minimized.
For each type of latch on the Progress database, this test measures the latching activity.
Output of the test : One set of results for every latch type on the target Progress database server that is to be monitored.
The measures made by this test are as follows:
| Measurement |
Description |
Measurement Unit |
Interpretation |
| Latch_busy |
Indicates the number of latches of this type that were busy per second during the last measurement period. |
Latches/sec |
|
| Latch_lock |
Indicates the rate at which the locks were held on this latch type during the last measurement period. |
Locks/sec |
A low value is desired for this measure. |
| Latch_spin |
Indicates the rate at which the process will spin again and attempt to get a latch of this type if the latch is not available immediately during the last measurement period. |
Spins/Sec |
|
| Average_lock_time |
Indicates the time for which the latch of this type was held. |
Seconds |
|
| Average_wait_time |
Indicates the average duration for which the sessions were waiting for latch of this type. |
Seconds |
Ideally, this value should be close to 0. The larger this value is, the more contention there is for latches and worse the performance of the database. If the wait time is high, check the SYSPROCESSES table of the database to see which latches are seeing most contention. |
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