By default, Oracle doesn’t index an entry if all columns within the index are NULL. However, (as I’ve blogged previously), it’s possible to index all possible NULL values by simply adding a constant value to the index column list. Importantly, the CBO knows when a column has all it’s NULL values indexed and can potentially […]
A recent question by Stalin Subbiah has prompted me to write a quick post on the reuse of empty leaf blocks. In part, the question asked: “Is there anyway I could monitor the effectiveness of empty blocks being reused from freelist of an index resulting from purge process that we are planning to start soon?” […]
The intent of this blog piece is just to bring together the whole discussion of block dumps and how we can use block dumps to demonstrate Oracle behaviour. First, let’s start with a fresh little demo, creating an index on a NAME column with 500 entries (note this specific demo uses an 11.2.0.1 database running [...]
Recent comments
2 years 52 weeks ago
3 years 12 weeks ago
3 years 16 weeks ago
3 years 17 weeks ago
3 years 21 weeks ago
3 years 43 weeks ago
4 years 11 weeks ago
4 years 40 weeks ago
5 years 25 weeks ago
5 years 25 weeks ago