Something went wrong…we need the database back to the point we have archivelogs of: List incarnation (just to see what we have…no actual need to) Restore database (getting the datafiles back in place) Recover database (creating an actual working database with all updates we can possibly find in the archives) Open the database (and start […]
Continue ReadingEmacs shortcuts
My most used emacs short-cuts: Alt – v : Scroll page up Ctrl – v : Scroll page down Ctrl – k : cut line into the yank buffer Ctrl – y : Yank line(s) (paste yank buffer) Ctrl – a : Move to the start of a line Ctrl – e : Move to […]
Continue Readingtmux
Tmux is one of the tools I really like to install as soon as possible. It provides the possibility of loosing your connection whitout loosing all your sessions, If you start tmux, it starts a “virtual” terminal. If you loose your connection to the machine, the vitual terminal keeps running. As soon as you can […]
Continue ReadingCreating a (demo)table
Often I need to create a table just for demonstration puposes, and this table needs to be filled up with data. The question for this post is…..: How to generate rows, preferrably a distinct number. So what I do? If the table has to be created yet: Or if the table allready exists: Did I […]
Continue Readingtnsnames.ora example
Because I tend to forget…this is what a tnsnames.ora looks like:
Continue Readinglistener.ora example
Because I always forget…this is what a lister.ora look like (example from a dataguard listener)
Continue ReadingOracle 19.5 Install
Just a headsup…. If you download Oracle RDBMS 19(.5), this a big zip file….. The place where you unzip is the place where oracle will make all the software. It actually is your new ORACLE_HOME. If you, for instance, place the zip file in /u04 because you have a lot of space there, and start […]
Continue ReadingBtree : Balanced tree index
Let’s draw a table (any table). For simplicity I say: a block can only cater for 4 rows The table has 2 columns (ID and Text) Oracle assigns a rownumber within the block for every row If I would like to see all rows where ID=154, Oracle would have to look in all blocks, and […]
Continue ReadingExtent Management And Segment Space Management
Storage in a Oracle datafile: A table or an index is called a segment on the storage side of the Oracle database. Such een segment consists of extents. And these extents consists of blocks (the smallest unit of storage in a Oracle database). Most databases I see have a db_block_size of 8K (8192 bytes). If […]
Continue ReadingHello world
I think Hello World is most appropriate for a first post.
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