Author: Admin

http://www.mail-archive.com/oracle-l@fatcity.com/msg79721.html Oh yeah, I forgot to say that in 9.2.0.3 the shared pool was broken up into “heaps” (Oracle terminology) but whatever fancy stuff they were trying to accomplish by doing this (I think part of the magical self-tuning initiative) was buggy and this hastened the fatal 4031 situation. There is a parameter (so I…

Read More “Another Tuning Article for subheap of shared pool” »

Note:396940.1 How many Subpools will I have by default? The number of subpools is calculated using a simple algorithm. First, a subpool must be at least 128MB in 9i releases and at least 256MB in 10g releases. Bugs and internal tests show that subpools around 500M will work most efficiently and in future versions, we…

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Here is the syntax: analyze index CUSTOMER_LASTNAME_IND validate structure; It populates the SYS.INDEX_STATS view only. The SYS.INDEX_STATS view can be accessed with the public synonym INDEX_STATS. The INDEX_STATS view will hold information for one index at a time: it will never contain more than one row. Therefore you need to query this view before you…

Read More “When to rebuld B-tree index” »

exp userid=cs file=gift_cert_07FEB07.dmp log=gift_cert_07FEB07.log compress=N grants=N tables=gift_certificate statistics=none query=”where dt_crtd >= to_date(’02-04-2007 10:00:00′,’MM-DD-YYYY HH24:MI:SS’)” /* WITH LOG */ imp userid=cs file=gift_cert_07FEB07.dmp log=gift_cert_07FEB07_imp.log ignore=Y grants=N fromuser=cs touser=cs statistics=none constraints=N buffer=10485760 commit=y indexes=N feedback=5000

When you create a composite B-tree index, you should consider the following. The most restrctive condition: The condition that returns the least number of rows. The column that is involved in this condition, should be the leading column of B-tree index. So for finding the candidate of composite index columns, column order should be.. (…

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Oracle 10g Histogram ==================== Oracle uses two types of histograms for column statistics (1) height-balanced histograms (2) frequency histograms The type of histogram is stored in the HISTOGRAM column of the *TAB_COL_STATISTICS views (USER and DBA). This column can have values of HEIGHT BALANCED, FREQUENCY, or NONE. (1) Height-Balanced Histograms In a height-balanced histogram, the…

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exp userid=cs file=zip_cutoff_01FEB07.dmp log=zip_cutoff_01FEB07.log compress=N grants=N tables=zip_cutoff statistics=none query=”where delivery_date >=trunc(sysdate)” imp userid=cs file=zip_cutoff_01FEB07.dmp log=zip_cutoff_01FEB07_imp.log ignore=Y grants=N fromuser=cs touser=cs statistics=none