In order to check size of table in Oracle database you may use following query:
When you are using Oracle SQL Developer 4 to connect to multiple databases at the same time (sometimes using credentials other than saved in connection properties) you have multiple tabs in main window labeled with DB names without any indication of under which account you are connected to them (it seems natural to have such information in tab label/name).
So your options here is either create multiple saved connections for each credentials used and name connections so that they reflect both DB name and credentials (after that using drop box in top right corner of main window comes in really handy) or use a query to check which credentials are currently being used.
You may use following query to check your currently used credentials:
\n[code language=”sql”]\nSELECT username,\nosuser,\nmachine,\nschemaname\nFROM gv$session\nWHERE sid=(SELECT sys_context(‘userenv’,’sid’) FROM dual);\n[/code]\nThis will give you USERNAME, OSUSER and MACHINE info. Or, alternatively you may use this (less details, but also less privileges required):\n[code language=”sql”]\nSELECT USER,SYS_CONTEXT (‘USERENV’,’SESSION_USER’) FROM dual\n[/code]\nThis returns USER and SYS_CONTEXT.
For Dummies series does amazing job in explaining everything in plain language without dramatic loss of depth or excessive oversimplification. They are very good to get you started with the subject.\nMy first tech book long time ago was Networking for Dummies (in Russian), and it was both fun to read and informative, all my tech knowledge prior that was based upon trial and error approach 🙂 Probably should re-read latest edition of Networking for Dummies for the sake of knowledge refresh and very good memories of 1st experience of for Dummies series :)\nAs for Oracle 12c book: I preordered digital edition from Amazon, and overall it nicely covers quite a wide array of things you need to know to approach Oracle 12c RDBMS. It seems that Oracle 12c system far more sophisticated/feature-rich platform than MS SQL Server – though probably I just don’t know MS SQL Server well enough (need to go through respective for Dummies book?). To some extent there is more to learn here platform wise as it can run both on top of Linux and Windows – so there are far more options and ramifications for deployment and configuring it.\nThe only bad thing about this edition is amount of very obvious typos/editing errors – didn’t expect that from respective brand/publisher. When language errors obvious even for non-native speaker it’s not what you want to allow as respective publisher I guess.
You may use following query to check Oracle version:
SELECT * FROM product_component_version
Or this one:
SELECT * FROM v$version
Both will return Oracle version information.