Month: October 2020

Index Range Scan

Index index OK, let’s talk about the Index Range Scan. The word range reflects that Oracle will scan through (a part) the index. As opposed to an Index Unique Scan where Oracle exactly knows what to look for and where, it just decends through the tree-structure. The Index Range Scan does not know how many …

Index Unique Scan

Main Post The Index Unique Scan is used when one unique piece of information (row) is needed. A primary key would be a perfect example. Since a primary key is 1) Not Null and 2) Unique. The uniqueness can be realized with a index…a unique index. This is actually a normal btree index, with the …

Index_demo data setup

In a number of posts about indexes I use a demo table with some indexes. Here is how it is created: drop table index_demo; create table index_demo as with engine as (select level l from dual connect by level<=1e5) select l n, round(l/100) d, mod(l, 100) m, dbms_random.string(‘l’,25) s from engine; prompt create indexes create …

SSL

Wow….that was easy. I just wanted to add SSL security to the website. I was prepared for : Creating a public and private key Creating a Certificate Signing Request (CSR) Issuing the CSR to a Certificate Authority (CA) Receving the signed certificate Configuring the Keys and Certificate in this very website. However …. Let’s Encrypt …

RMAN recipes

A few recipes I like to go through: Restore and recover a database as far as we can go Restore and recover a database up to a point in time Restore and recover a database when datafiles are awol. Restore and recover a database when the controlfiles are missing Restore and recover a database when …