How not to write subqueries:
AND sal.ticket_airline || sal.ticket_number NOT IN ( SELECT sub.dsd_airline || sub.dsd_ticket_number FROM ... )
If there had been any opportunity for the optimizer to do something clever with the NOT IN, you’ve just made sure it can’t happen. On top of that you may find that you don’t get the right results – consider the following cut-n-paste:
CRN, a leading publication for VARs and Technology Integrators, reports on the IDC second quarter 2013 revenue report for the worldwide integrated infrastructure and platforms. This market grew 50.2 percent over revenue for second quarter 2012 to reach $1.3 billion.
Read the full article "Oracle Leads The Pack As Converged Infrastructure Q2 Sales Surge", by Joseph F. Kovar
While smart mobile devices afford countless modern conveniences and allow for constant connection, some are beginning to see the darker side of the mobile revolution, according to Forbes. Internet users have long been familiar with the phenomenon of companies tracking browsing history to create targeted advertisements, but eyebrows are being raised at the new trend of customer location tracking to optimize retailers' marketing efforts.
Detailing an Oracle Database process's CPU consumption is amazing, a lot of fun, and can lead to some “ah ha” moments. To make this posting daily digestible, I’m breaking it up into a multi-part series. Today I’m posting the second part entitle, Tools Options. Here we go…
Big data is only getting bigger. As the amount of digital data increases exponentially in the coming years, mobile platforms will be the primary source for the growing flow of information and database quality, according to a recent report from Business Insider that examined a BI Intelligence study. Canadian Bank CIBC predicted that the quantity of data will grow by a multiplier of 50 over the next 10 years.
This morning when I came at work I discovered that all the redo log files (current, active, inactive..) have been removed from one of our database (useless to say by mistake) resulting in:
Performance tuning is all about time. You measure the time it takes for a certain process to complete, and then you search for ways to reduce this time to improve end-users experience and/or increase the application productivity. But minimizing time is not enough — it’s important to minimize the correct time metric. A typical mistake in database performance optimization to optimize DB time instead of the duration experienced by the end user.