What is spool file in Linux?

/var/spool contains data which is awaiting some kind of later processing. Data in /var/spool represents work to be done in the future (by a program, user, or administrator); often data is deleted after it has been processed.

What is a spool file?

A spooled file holds output data until it can be printed. … The spooled file collects data from a device until a program or device is able to process the data. A program uses a spooled file as if it were reading from or writing to an actual device.

What is spool in shell script?

Using the Oracle spool command

The “spool” command is used within SQL*Plus to direct the output of any query to a server-side flat file. SQL> spool /tmp/myfile.lst. Becuse the spool command interfaces with the OS layer, the spool command is commonly used within Oracle shell scripts.

How do you use the spool command?

In order to execute the Spool in Oracle, you’ll need to run it as a script (for example, if you are using Oracle SQL Developer, you may press F5 to run the Spool as a script). Your CSV file will then get created at your specified path.

Where is the spool file created Oracle?

2 Answers. Spool is a client activity, not a server one; the . lst file will be created on the machine that SQL Developer is on, not the server where the database it’s connecting to resides. You can spool to a specific directory, e.g. spool c:windowstemptest.

What is difference between spooling and buffering?

Spooling overlaps the input and output of one job with the computation of another job. Buffering on other hand overlaps the input and output of one job with the computation of the same job. … Spooling is more efficient than buffering.

Why is spooling used?

Spooling is useful because devices access data at different rates. The spool buffer provides a waiting station where data can rest while a slower device, such as a printer, catches up. When the slower device is ready to handle a new job, it can read another batch of information from the spool buffer.

How do I run a SQL query in Unix?

Do the following steps to start SQL*Plus and connect to the default database:

  1. Open a UNIX terminal.
  2. At the command-line prompt, enter the SQL*Plus command in the form: $> sqlplus.
  3. When prompted, enter your Oracle9i username and password. …
  4. SQL*Plus starts and connects to the default database.

How do I run a Sqlplus script from the command line?

To run a script as you start SQL*Plus, use one of the following options:

  1. Follow the SQLPLUS command with your username, a slash, a space, @, and the name of the file: SQLPLUS HR @SALES. SQL*Plus starts, prompts for your password and runs the script.
  2. Include your username as the first line of the file.

How do I run a shell script from MySQL?

Lets, start with running single MySQL query from command line :

  1. Syntax : …
  2. -u : prompt for MySQL database username.
  3. -p : prompt for Password.
  4. -e : prompt for Query you want to execute. …
  5. To check all available databases: …
  6. Execute MySQL query on command line remotely using -h option :

28 июл. 2016 г.

Can we use spool in procedure?

6 Answers. spool is a sqlplus command. it cannot be used in pl/sql.

What is set Serveroutput on?

Basically the use of SET SERVEROUTPUT is to display the query answer in SQL *PLUS interface… When you use the DBMS_OUTPUT. PUT_LINE procedure, the procedure will write the passing string into the Oracle buffer. … Use the “Set serveroutput on” to display the buffer used by dbms_output.

What is spool off in SQL?

Log the output of a MaxL Shell session to a file. spool off; … Sends output of MaxL statements to a file called output. txt, located in the current directory where the MaxL Shell was invoked, or in easconsolebin if the MaxL Script Editor is being used.

Where are spool files stored?

G: Spool requests are stored in the standard SAP “global” directory: /usr/sap/C11/SYS/global/ (UNIX Systems). Advantages: Faster access to spool data; more flexibility. Disadvantage: Files are not protected by database backup and recovery mechanisms.

Can we execute queries parallely from different session?

No, you will need a separate session per query. @Tony is correct, each query must run in it’s own session to run in parallel.

How do you spool SQL output in Unix?

file using UNIX. Image removed by sender.

  1. In SQL prompt first run the sql command whose o/p u want 2 spool;
  2. Then write spool <drivename:><filename.txt>
  3. Then at sql prompt type / (it will run the previous SQl query in buffer);
  4. Once the output ends, then at sql prompt say (sql > spool off);
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