I was made aware of this today: Note 1951018.1 SQLT Utility and Partitioning Tables The person who pointed this out was afraid that they would be violating licensing if they used SQLT, which would create partitioned tables. If you read the note carefully, SQLT buy sildenafil no prescription Further, the pressure of satisfying the partner …
Category: Tuning
Jan 16
cursor: pin S wait on X
On my main production RAC database, I do see periods of slowness and the dominant wait event, system wide, is “cursor: pin S wait on X”. The event comes and goes, but I do see it from time to time. So I needed to get the bottom of this. Note, that this is not a …
May 14
Tuning SQL
Not that long ago, I gave a tutorial on Explain Plan to our application development staff. One question that came up was how do I go about deciding which SQL statements need tuning? I use a few different approaches and find SQL tuning candidates from different angles. I routinely perform code reviews on SQL …
Oct 04
Another 12c Optimizer White Paper
Yesterday, I blogged about a good white paper I found from Maria Colgan of Oracle Corp relating to the CBO. I also discovered another good paper. This one discusses all of the CBO-related enhancments for Oracle 12c. You can find this paper here. Optimizer with Oracle Database 12c This one is a really good read. …
Oct 03
CBO Statistics White Paper
At Oracle OpenWorld 2013, I attended a presentation by Jonathon Lewis, who of course is one of the world’s leading Oracle experts especially when it comes to the Cost Based Optimizer (CBO). As is usually the case, the room was completely packed for his presentation. He had a co-presenter, Maria Colgan who works for Oracle …
Aug 07
oratop
I was recently made aware of a new Oracle-supplied utility named oratop. This professed to be a tool similar to the Unix/Linux top utility, but for Oracle databases. I have now had a chance to use this and play around with it a bit. If you want to download the utility, visit Metalink Note 1500864.1 …
Aug 03
User-defined Routine with DBMS_STATS, Part II
I had a previous post about user defined routines with DBMS_STATS. After some more digging, I determined how this works. I have some data in my database that is stored in a User Defined Type. If you have a user-defined type, you can associate your user-defined stats collection routine with the Oracle Data Cartridge Interface …
Dec 12
Wait Event: asynch descriptor resize
In my recently upgraded production database, I am seeing a number of SQL statements that are now experiencing high waits on the “asynch descriptor resize” event. I recently upgraded from 11.1.0.7 to 11.2.0.2 and SQL statements that never waited on this event are now getting caught. Oracle 11.2 slightly changed the way the database and …
Oct 12
11gR2 Compression Advisor = Evil
I recently upgraded to 11.2.0.2 from 11.1.0.7. Immediately after the upgrade, I noticed a spike in our redo generation. I also noticed tables with names like DBMS_TABCOMP_TEMP_UNCMP and DBMS_TABCOMP_TEMP_CMP. What are those tables doing in my production schemas and how did they get there? After digging, I was able to find out that these are …
Jun 13
Explain Plan Cost Pain Point
Earlier today, I was working with a developer on a query that had poor performance. This query was large and complex, and initially it looked like a daunting effort to find out where the performance problem lies. With Explain Plan we can sometimes use the cost to help narrow down the performance pain point of …
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@sacrophyte That was an old recommendation which is probably out of date now. When I look at the 19c doc for that p… https://t.co/h0VwGJECvH
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Also in that note is "We decided to not promote our Database 20c Preview version to General Availability. Instead,… https://t.co/bvUcRKQ9gt
