How locks work with move partition ONLINE on Oracle 12c

With the release 12c Oracle introduced the “online partition movement” making the operation a non-blocking DDL command. This means that it’s possible to run any DML on a partition while the same is being “moved” using the new ONLINE option.
Let’s see how that works on our usual test table populated with 1 million rows in the first partition

We can now take a look at how move partition works normally when not running it in ONLINE mode.
Let’s execute

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SQL Plus and the dark power of the character # (hash or pound)

Not everybody knows that in SQL Plus the character # (called hash or pound) has a special use that I discovered it myself not much time ago. Well, it’s not really a secret, you can read about it on the official SQL Plus manual, but it’s rarely used. The sign #, in fact, is the default character used as SQLPREFIX during a SQL Plus session and can be changed executing the command

SET SQLPRE[FIX] prefix_char

But what does it do? It tells SQL Plus to execute a SQL Plus command while in the middle of entering a SQL statement or a Pl/Sql block of code.
For example you are writing a select statement

and, while writing down the list of columns to extract, you don’t remember the name of one of them. Normally you would quit writing the query, execute a desc of the table and start writing it again from scratch. But the # sign give us another possibility. All you have to do is enter a new line, digit the magic sign # and write the desc you need

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