Using ST04 Transaction to Analyze Oracle Database

ST04 is a very good transaction to analyze database performance. To use it reliably, you need to reset the statistic using the reset button and check the new values after a few days' use to populate with new values and analyze it by using Since reset.

Time/User call should be less than 20ms. Note that the value can be much higher due to the inclusion of special idle events which limits the relevance of this data.

The ratio of Busy wait time to CPU time should be close to 60:40. This is an indication of a well-tuned system. If you see very high values (such as 80:20), system performance can be improved using 'wait event tuning'.  If the CPU time is significantly higher than 40%, check the CPU utilization on the database server.


Hit ratio (Quality) of the data buffer should be more than 94%. A low hit ratio might be due to small size of the data buffer.Chek SAP note 619188 for a deeper analysis.

Reads/User Calls should be less than 15. If it is too high, check for expensive SQL statements. Check SAP Note 766349.

Go to Detail Analysis Menu -> File System Requests and check the average read time (Avg(ms) for Blk Reads) for individual data files or in total (Total under the column). If the values is very high in comparison to 10 ms, check whether the problem can be solved by improving the data distribution or if there is any Disk I/O problem at hardware level.
You can analyse more on disk usage from ST06/OS07 (-> Detail Analysis Menu -> Disk). If the load on the database server's disks is more than 80%, you need to redistribute the data files.

DD-cache quality should be more than 80%;  pinratio should be more than 95%;  reloads/pin should be lower than 0.04; User/recursive calls should be more than 2. If there is too much deviation in these indicators, you need to increase shared pool size.

Comments

Post a Comment

Popular posts from this blog

OS/DB Migration - CMD. STR, TOC, EXT, R3load, DDLDBS.TPL and more

Image
With increasing need to improve performance or reduce costs or vanishing support for operating systems/databases it becomes inevitable to migrate to a better OS or DB. We feel take a quick look at the primary ingredients of the tools for OS/DB migration handled by R3SETUP. Tools - R3load, R3ldctl and R3szchk R3ldctl creates STRucture files, TemPLate files by reading the technical settings for table/indexes in SAP data dictionary. R3szchk calculates the database size object sizes (EXTent files) for the target system based on the STR files created by R3ldctl. The EXT and STR files can be later split into smaller groups. The most crucial tool R3load is responsible for unloading and loading data from the database. R3load uses the files created by R3ldctl and R3szchk and dumps the data into compressed binary format as .001, .002 .. files. It uses cmd files to achieve the task. If the cmd files are not present, it creates on its own. Files Command files*.cmd  are created i
Read more

Fixing Inconsistent Table - Table activation fails due to inconsistency between DD and DB

If you find a table to be available on the database, but not active in ABAP dictionary, try calling SE14 as DDIC user, enter the table name and choose Table > Reconstruct, Execute. If this method fails follow these steps: Call transaction code SE37 and execute the function module  DD_TABL_ACTM with single test On the next screen, do not change any other field except the following and set them as shown below: MODE: 12 NTAB_PUTSTATE: N TABNAME: <enter the correct table name> Click on Execute The export parameter ACT_RESULT should show 0. To verify if the inconsistency is fixed, call transaction SE14 > Extras > Database Object > Check and  SE14 > Extras > Runtime object > Check.
Read more

301 Redirect Using SAP Web Dispatcher

301 redirects are typically used to redirect accesses that include www to non-www or vice-versa. Example, when you call http://blogger.com, the call is redirected to www.blogger.com. An end-user may prefer to call a URL in any manner. You must ensure that all these calls are redirected to relevant URLs with content. SAP web dispatcher can be configured to send a redirect (301) to the client. To enable redirection add icm/HTTP/redirect_<xx> to the web dispatcher's profile file. The parameter uses the following syntax: icm/HTTP/redirect_<xx> = PREFIX=<URL prefix>[, FROM=<pattern for URL>, FROMPROT=<incoming protocol>, FOR=<pattern for host name:port>,TO=<new URL prefix>, PROT=<protocol>, HOST=<host>, PORT=<port number/name>] Let's say you want to redirect all the HTTP requests on mysource.com on 80 port to mytarget.com on HTTPS 443 port icm/HTTP/redirect_0 = PREFIX=/, FROM=*, FROMPROT=http, FOR=mysource.com:80,
Read more