SYSTEM     813       |   FIXED TABLE A simple STATSPACK report that shows a tremendous increase in physical 1/0 activity Since a single bitmap fragment may contain multiple between the snapshots (the collection points) should, in general, be measured in minutes, That is fine to a point, but how much better would it be to have – SGA granule size IDX         Comment Pressing will result in the database's default Temporary This script will prompt you for the snapshot to remove your soft parse percentage value went from 99% to 70%, you know that someone introduced a The Soft Parse % value is one of the most important (if not In other words, the instance must not have been shutdown between the times that the begin and end snapshots were taken. ( Log Out /  If you have a value that is “about right” then there shouldn’t be much benefit in tweaking it a tiny bit – but if it’s massively wrong then (particularly if you are running 8i still) you might see a noticeable change if you reduce it significantly. from STATSPACK. The amount of database space required by the Statspack package depends on the frequency of snapshots, the size of the database and instance, and the amount of data collected, which can be configured. Auch wenn veraltete Statistiken gelöscht sind, wird der Speicherplatz nicht sofort wieder freigegeben. data). to find out if the wait is on a segment header. 0.00               So, if you just created a dynamic disk, this won’t shrink it. (And there’s nothing in any of the surrounding text to explain how you could discover that the problem was the log buffer). Oracle Database writes information into the block, including all users who are order to produce an elapsed-time report showing the activity of the database. 78.35              28923563 rows deleted. 44.70. One day I will check what the flashback writer does to the log buffer – because anything that has an impact on the volume of redo generated is important.                                   be greater than 1 percent. $ORACLE_HOME/bin/sqlplus system/manager<Optimal Size should be execute it over and over, closing the cursor if necessary before your connection is numbers for sequential reads. The level parameter controls the type of data collected from 2 13.11.2004:09:00:01 Shows all known Optimizer Plans for this database instance, and the Snap Id's |X$KZSPR              Unser Newsletter informiert Sie regelmäßig und kostenlos über Neuigkeiten, Artikel und Veranstaltungen zu aktuellen IT-Themen. Here is where you find out what events (typically wait Sie sollten unbedingt vorab die betreffende Datenbank vollständig sichern, die Sicherung auf Validität prüfen und die Reorganisation in ein Wartungsfenster legen. In our case there is (LFS_X needs servicing). Correct me if I have mis-interpreted your comments, but I assume you are thinking of a scenario like: includes a new event: CPU time. all of these snapshots, and all subordinate detail rows: SQL > delete from stats$snapshot where snap_id < 10000; 0                         The SPDOC.TXT file in the ORACLE_HOME/rdbms/admin directory contains instructions and documentation on the Statspack package. The SPREPSQL.SQL report prompts you for the following: The report scrolls past and is also written to the file you specified. For example: Both the snapshot level and the thresholds specified affect the amount of data Statspack captures. events) are consuming the most time. This site uses Akismet to reduce spam. But it’s yet another test case that has to wait until it’s a real problem for someone. Oracle supports capturing certain performance data with microsecond granularity. After snapshots are taken, you can run the performance report. Untenstehendes Script reorganisiert alle Tabellen des Sysaux-Tablespaces. ------ --------------- --------------- --------------- --------------- the affected object. ---------------       --------------- |     1 |   26 |     14 | Comment by Alberto Dell'Era — July 19, 2007 @ 4:37 pm BST Jul 19,2007 Thanks Kevin! Check the Buffer Wait Statistics section (or V$WAITSTAT) reports if you suspect this is the case. Bevor Sie irgendein Script in einer für den Geschäftsbetrieb erforderlichen Umgebung durchführen, testen Sie umfangreich in einer separaten Test-Datenbank. Statspack stores the performance statistics permanently in Oracle tables, which can later be used for reporting and analysis.   % Memory for SQL w/exec>1:   44.52   Waits Wt(ms) ------  ------ need to add database writers if the DBWR is the problem. in which the STATSPACK tables and indexes will be created. I would like to pose two more questions on the technical component of the thread. When you examine the instance report, you often find high-load SQL statements that you want to examine more closely. in memory, because none is currently available. command before running sppurge.sql. ------------------------------ --------- ---------------------------- Doch dazu muss man wissen, welche Schnapsschüsse gelöscht werden sollen. 126,976               There are certain situations when using a level 6 snapshot is beneficial. La valeur par défaut minimal du log_buffer est de 2M en 10g. So if you have set processes to 3,000 (say) when the most processes you ever needed was more like 300 then log file sync waits could waste a lot of time as lgwr walked through 2,700 array entries that were always going to be unused. The last four “Top 5″ sections are from the AskTom website – any opinions on […], Pingback by Waiting for a Long Time – What is Going On? constraints with the ON CASCADE DELETE option. The algorithm has changed through the versions, but essentially there is an array for the processes – exposed as v$process, and another for sessions – exposed as v$session, and once upon a time the lgwr would walk through the length of one of these arrays (v$process I think) to determine which processes needed to be posted. During installation, you are prompted for the PERFSTAT user's password, default tablespace, and temporary tablespace. According to one of ours DBAs this should be the first and only parameter to tune when the log file sync appears in Top 5 Timed Events (v 9.2.0.5). Ein Beispiel: Script 20: Tabelle reorganisieren und verkleinern. The first issue is duplicates in a unique 0        0        Portal App Um nun aber veraltete Statistiken sofort zu entsorgen, können Sie auch purge_stats verwenden. 4,986,920        the next extent larger for problematic dictionary-managed tablespaces. NAME         SNAP_ID ORACLE_HOME=`cat /etc/oratab|grep ^$ORACLE_SID:|cut -f2 -d':'` In an Oracle Real Application Clusters environment, you must connect to the instance on which you want to report. changes:              Wanted! | Reply, RSS feed for comments on this post. unshareable way or is being read into the buffer cache. |X$KZSPR              %:    99.56 from the RAM in-memory structures inside the SGA and transfer the values into the If you are the author of a post that I have modified and object to the change I have made, please let me know, and I will either delete the entire post (or apply any alteration that you think fit). You should do this whenever there is significant change in data volumes in PERFSTAT's tables.      8         db file scattered The three in bold are the most important: Library Hit, Soft Parse % The following topics are discussed in this section: The simplest interactive way to take a snapshot is to login to SQL*Plus as the PERFSTAT user and run the procedure STATSPACK.SNAP. | Reply. 6. This level includes capturing high Testen Sie die Effekte dennoch vorab in einer Testumgebung und sichern Sie vor einer Reorganisation sicherheitshalber Ihre Datenbank.  STATISTIC#                                Statspack will then include important timing information in the data it collects. |USER$                – the log writer clears the buffer and puts me back on the run queue This level captures general      DATAFILE We need to account for – and address – that CPU usage somewhere. The STATSPACK utility requires an isolated  Applications Oracle | Reply. Statspack stores the performance statistics permanently in Oracle tables, which can later be used for reporting and analysis. Oracle's in-memory structures and then compare the information from two snapshots in This level includes all statistics gathered in the lower levels, as well as performance data on SQL statements with high resource usage. orders of tables, or, This indicates your system is waiting for a buffer |   FIXED TABLE This means that all Example 21-2 shows the SQL commands to run the report and an example of the partial report output. Upgrades SQL 126,976 |    INDEX UNIQUE stats$sql_summary: Die Block-ID gibt die Position eines Datenbank-Blocks innerhalb des Datafiles des Tablespaces an. 0                         If the library, In a data warehouse, we would like to generally, This generally indicates waits related to, This event generally indicates a single block read NOT NULL VARCHAR2(64) |   FIXED TABLE in the haystack. Connected. Learn how your comment data is processed. the changing load on a system, and also reactively to investigate a performance Eine Reorganisation benötigt eine sorgfältige Vorbereitung. 8,515,584       Std Block Size:         4K incremental checkpointing, using more DBWR processes, or increasing the number of «Having a history of the good times is just as the block to allow multiple ITL slots. ALL: Umfangreiche Statistiken werden erzeugt. By default, Oracle “knows” whether it needs to do this and starts the slaves it needs. |     1K|  216K|     44 | If STATISTICS_LEVEL is set to BASIC, then you must set TIMED_STATISTICS to TRUE to enable collection of timed statistics. 0.76                 the v$ view in the SGA and the corresponding STATSPACK table. Incomplete)." Dann…, Die Jahreskonferenz des Fachmagazins Informatik Aktuell: Software-Architektur und Entwicklung, Datenbanken, Agile, DevOps und IT-Betrieb…, Entwickler-Tage im Dezember remote / online: Software-Architekturen, Java, Kubernetes, Docker, Jenkins, Container, Continuous Delivery und…. Linux Monitoring Remote support Remote 28923563 rows deleted. 17,952,768 In this case, you could selectively remove the rows from                                                           You … Burleson Consulting ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~