I saw this very odd statement on an SAP system last week.
SELECT /*+ AVOID_FULL ("/bic/xxx") */ * FROM "/BIC/XXX" WHERE "/BIC/XXX"=:A0
I had never seen that hint before so I thought I’d do a little investigation. First I did a quick check on a test case to see if it worked.
SYS@DEMO1> select /*+ avoid_full(a) */ count(*) from kso.skew a where col1=234657;
In a series of blog articles I show how you can instrument your ADF Application key actions. Instrumenting gives visibility and insight of what is happening inside the ADF application and in the ADF framework (what methods and queries are executed, when and how often). These runtime diagnostics can be very effective in identifying and solving performance issues. This enables developers to diagnose and solve performance problems at an early stage and to build an efficient, (more...)
Funny that oracle can easily cast ‘nan’,'inf’,'infinity’,'-inf’,'-infinity’ to corresponding binary_float_infinity,binary_double_nan, but there is no any format models for to_char(binary_float_infinity,format) or to_binary_***(text_expr,format) that can output the same as to_char(binary_float_infinity)/to_binary_float(‘inf’) without format parameter:
If a BINARY_FLOAT or BINARY_DOUBLE value is converted to CHAR or NCHAR, and the input is either infinity or NaN (not a number), then Oracle always returns the pound signs to replace the value.
SQL> select to_binary_float('inf') from dual;
Registration is now open for Oracle Midlands Event #3 on Tuesday 20th May..
As I mentioned in a previous post, Christian Antognini will be the speaker for both the sessions this time. He’ll be covering “12c Adaptive Query Optimization” and “Row Chaining and Row Migration Internals”.
Red Gate Software have kindly offered to sponsor the event again, so registration is free!
I’ve already registered. Please make the effort to come along and support the (more...)
Yes that is true, i said it, cellcli can lie to you there are some special cases were the output of cellcli is not the reality and you should double check it’s output with your standard OS tools. So this the output if dcli calling cellcli on an Exadata rack from an client:
[root@dm01db01 ~]# dcli -g cell_group -l root cellcli -e list cell attributes cellsrvStatus,msStatus,rsStatus
dm01cel01: running running running
dm01cel02: running running running
Great shout out for the Oracle Applications Cloud Release 8 Simplified UI by all-round Oracle Applications UX champ and enterprise applications guru Floyd Teter (@fteter). He tells us: “Simple is the new cool.”
Simplified UI Home Page. A tablet-first crisp experience from the cloud.
Nicely put. But, if that’s not enough kudos, try this Dutch language article, “Oracle doet hip en demonstreert interfaces”. The article is about the AMIS-hosted (more...)
Tech startups have a key role to play in bringing out change in enterprise user experience (UX), as pointed out in this great Wired article: Enterprise UX: Why the Paradigm Shifts.
Now, there are many nuances to enterprise-level user experience and the stakeholders are different to the consumer UX space, even though the consumerization of information technology driven by users expectation is now a given. Innovation in the startup space ultimately influences consumers before the (more...)
Overview of table functions
Table functions are functions that produce a collection or rows (either a nested table or a varray) that can be queried like a physical database table. You use a table function like the name of a database table, in the FROM clause of a query. The difference with a physical database table in the FROM clause of the query is that you need to use the TABLE() operator to tell the (more...)
In previous posts about caching mechanism of determinstic functions I wrote that cached results are kept only between fetch calls, but there is one exception from this rule: if all function parameters are literals, cached result will not be flushed every fetch call.
Little example with difference:
SQL> create or replace function f_deterministic(p varchar2)
2 return varchar2
7 return p;
SQL> set (more...)
Prior to Oracle 12c truncating tables with dependent children was a pain. We had to disable the constraint before truncating the parent table followed by enabling the constraint. The performance gain achieved using TRUNCATE instead of DELETE almost disappeared if the constraints were enabled with VALIDATE option. If enabling the constraint with NOVALIDATE option was not acceptable, then DELETE seemed to be the only way to go.
Starting with Oracle 12c , Oracle supports truncating (more...)
The Gartner 2014 Advanced Analytics Quadrant is out now. Well it is if you can find it.
Some of the companies have put it up on their websites to promote their position.
For some reason Oracle hasn't and I wonder why?
You can see that some typical technologies are missing from this, but this is to be expected. How much are companies really deploying these alternatives on real problems and in production. Perhaps the positioning (more...)
It’s possible to get an error after granting privileges to an external file system. One of those errors is tedious to resolve until you understand the rules governing Java NIO file permissions.
You grant privileges to external file systems as the
sys user with the
grant_permission procedure of the
dbms_java package, like
5 ,'read' (more...)
I recently hit the problem covered in MOS note “ASM Instance Is Not Coming Up ORA-00064 (1,4468736,Kfchl Array) Kfchl Array (Doc ID 1328620.1)” mid-way through a Grid Infrastructure upgrade from 22.214.171.124 BP16 to 126.96.36.199 BP3 on Exadata. Specifically, it was the application of prerequisite patch 17783101 (required for downgrades) to node 3 that hit the problem. At this point nodes 1 and 2 had been successfully patched (more...)
This question came up at the recent World Wide Data Vault Consortium. Seems there are still many folks who build a data warehouse (or data mart) that do not include FKs in the database. The usual reason is that it “slows down” load performance. No surprise there. Been hearing that for years. And I say […]
Description This query return the top 10 queries by resource consumption (CPU+IO+WAIT) in the last hour from v$active_session_history. Be careful, this view is part of the diagnostic pack, you should not query this view if you don’t have license for it. top 10 queries from v$active_session_history [crayon-533b91631cebb871999454/] This query return top queries by resources consumed, [...]
The post Top 10 queries from v$active_session_history appeared first on Oracle DBA Scripts and Articles.
We had a client that was running into a strange issue on their Exadata where new connections coming in through the SCAN were failing. After doing some troubleshooting, it was discovered that it was related to one of the SCAN listeners not properly accepting requests from new sessions. The VIP and listener were running, and everything looked normal.
We had the following SCAN setup:
I’m a little behind on my updating my blog with images of conferences where I will be speaking (I’ll get to that later and hopefully fix it). In the meantime, I wanted to let everyone know that I will be speaking at IOUG Collaborate 2014 this year. IOUG has decided to hold the conference in Las Vegas, NV. Should be a fun conference; after all everyone knows the saying “What happens in (more...)
I frequently am asked questions that boil down to:
- When should one use NoSQL?
- When should one use a new SQL product (NewSQL or otherwise)?
- When should one use a traditional RDBMS (most likely Oracle, DB2, or SQL Server)?
The details vary with context — e.g. sometimes MySQL is a traditional RDBMS and sometimes it is a new kid — but the general class of questions keeps coming. And that’s just for short-request use (more...)
One of the problems of “knowing” so much about Oracle is that the more you know the more you have to check on each new release of the software. An incoming ping on my posting “Lock Horror” reminded me that I was writing about 188.8.131.52, and the terminal release is 184.108.40.206, and the whole thing may have changed in 220.127.116.11 – so I ought to re-run some tests (more...)