What is the use of $$ sign in table name in Oracle Database

Question

I get to maintain a application which use $$ sign as prefix and suffix to some word in the table create statement - Oracle DB. like

create table $$temp$$(id int)

For testing purpose I ran the statement in SQL plus but it threw invalid character error and so I had to remove $$ sign and then it ran as expected.

Is there a specific use for $$? some thing related to session ?

Answer 1

Is there a specific use for $$

No there is not. Dynamic performance views, however, have one dollar sign ($) in their names, v$sql, for example. It's Oracle's choice to name them that way.

You won't be able create a table, which name starts with dollar sign($), simply because any non-quoted identifier should begin with an alphabetic character. You can however force Oracle to accept an identifier that begins with a non-alphabetic character if you enclose it with double quotation marks, like so

create table "$$temp$$"(
  id int
)

but it should be noted that when you created a table using double quotation marks, you made that table name case-sensitive (unless you didn't type the table name in uppercase) and would always have to use double quotation marks when referencing that table.