Kbase P147615: What are the performance impacts of running idxcheck online?
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
8/16/2010 |
|
Status: Verified
GOAL:
What is the performance impact of running idxcheck online?
GOAL:
What is the impact of idxcheck on other users when ran online?
GOAL:
Are there any benchmarks regarding running idxcheck online?
FACT(s) (Environment):
All Supported Operating Systems
OpenEdge 10.1C
FIX:
Progress does not have benchmarks associated with individual maintenance utilities. The major factors associated with the performance impact of running idxcheck online is the amount of data being processed and competition with other processes.
Online idxcheck is a highly I/O bound process. The performance impact of running idxcheck online varies depending upon how heavy the competing processes are. As a reader, there might be mutual exclusions between idxcheck and other writers on the same block, record, key etc. In general, the competition in Type I areas can involve more users because idxcheck reads record blocks and index blocks. Those blocks may belong to other objects, and the process will need to read them to find out. In Type II areas, this is different. Idxcheck only processes the blocks of the indexes to be checked and the blocks of the host table.
Another consideration with idxcheck is the fact that the Database Administrator has the option of locking the tables while the idxcheck process is running by using the "L, "Lock the tables during the check" option. When idxcheck is running with the "L, Lock option", idxcheck locks tables in a shared mode, to block exclusive accesses to the table.
One additional consideration is that schema change requests are also blocked if and online idxcheck is running.
To reduce contention with other processes, idxcheck can be ran with the "-NL, No Lock" parameter on startup. This parameter will result in the idxcheck utility being ran in a manner that index admin and records are not locked during the idxcheck process. The trade off is the accuracy of the result.