Oracle Indexes

One of the very cool new features introduced in Oracle Database 12c Rel 1 is the ability to store JavaScript Object Notation (JSON) documents within the database. Unlike XML which has its own data type, JSON data can be stored as VARCHAR2, CLOB or BLOB data types, but with a JSON check constraint to ensure the […]

I’ll be presenting the next round of “Let’s Talk Database” events around Australia and NZ this winter in July/August 2016. These are free events but due to limited places have often “sold out” in the past, so booking early is recommended to avoid disappointment. All events run between 9:00am – 12:30pm and are followed by a networking lunch. We always have […]

In my last couple of posts, I’ve been discussing how storing date data in a character based column is a really really bad idea. In a follow-up question, I was asked if storing dates in NUMBER format was a better option. The answer is that it’s probably an improvement from storing dates as strings but it’s […]

In the previous post, I discussed how storing date values within a character data type is a really really bad idea and illustrated how the CBO can easily get its costings totally wrong as a result. A function-based date index helped the CBO get the correct costings and protect the integrity of the date data. During […]

For something that’s generally considered an extremely bad idea, I’ve lost count of the number of times I’ve come across applications that insist on storing date values as characters within the database. We’ve all seen them … I recently got called in to assist a customer who was having issues with a POC in relation […]

This of course is an April Fools joke. Sorry !! A very exciting announcement !! I’ve recently been promoted within Oracle Corporation to lead their brand new Oracle Cloud offering “Indexing as a Service” (IDXaaS) team, based on my previous work and experience in the indexing space. Yes, I’m both thrilled and excited to be […]

I’ll be presenting a new round of “Let’s Talk Database” events around Australia and NZ next month. These are free events but have often “sold out” in the past so booking early is recommended to avoid disappointment. All events run between 9:00am – 12:30pm and are followed by a networking lunch. Currently, the confirmed events are: Sydney – Tuesday, […]

It’s been a very tough week so to help keep my mind off rather sad events, thought I’ll finish off one of my unpublished articles. Initrans is a physical attribute that determines the initial number of concurrent transaction entries allocated within each data block for a given table/index/cluster. Every transaction that updates a block has to acquire an […]

In mid-April 1979, as a nerdy 13 year old, I sat in my bedroom in Sale, North England listening to the radio when a song called “Boys Keep Swinging” came on by an singer called David Bowie who I never heard of before. I instantly loved it and taped it next time it came on the radio via my […]

This come up recently with a customer and I saw a related question on OTN that made me realize I haven’t previously discussed the SKIP_UNUSABLE_INDEXES parameter. Let me start by making a very simple point. All it potentially takes to make your entire database effectively inoperable or indeed to maybe bring down a RAC instance is […]