As SQL*Loader executes, it may create a file called the discard file. … The discard file therefore contains records that were not inserted into any table in the database. You can specify the maximum number of such records that the discard file can accept.
Which are the contents of discard file in SQL Loader?
Discard file: The discard file contains rows that were discarded because they were filtered out because of a statement in the SQL*Loader control file.
What is control file in SQL Loader?
The SQL*Loader control file is a text file that contains data definition language (DDL) instructions. DDL is used to control the following aspects of a SQL*Loader session: Where SQL*Loader will find the data to load. How SQL*Loader expects that data to be formatted.
What are the different types of files used in SQL Loader?
This release of SQL*Loader supports loading of four LOB types:
- BLOB: a LOB containing unstructured binary data.
- CLOB: a LOB containing character data.
- NCLOB: a LOB containing characters in a database national character set.
- BFILE: a BLOB stored outside of the database tablespaces in a server-side operating system file.
What is filler in SQL Loader?
SQL LOADER lets to skip unwanted fields in the data file by using the “FILLER” clause. Filler was introduced in Oracle 8i. SQL LOADER also lets you load the same field into two different columns of the table. … This can be achieved using POSITION (1) clause which takes you to the beginning of the record.
What command is used to invoke SQL Loader?
The EXTERNAL_TABLE = EXECUTE qualifier tells SQL*Loader to create an external table that can be used to load data and then execute the INSERT statement to load the data. All files in the external table must be identified as being in a directory object.
What is external table in Oracle?
External tables allow Oracle to query data that is stored outside the database in flat files. The ORACLE_LOADER driver can be used to access any data stored in any format that can be loaded by SQL*Loader. No DML can be performed on external tables but they can be used for query, join and sort operations.
Is SQL Loader an ETL tool?
Is SQL Loader an ETL tool? But these tools typically can’t take advantage of the high-performance capabilities of the ETL tools, or the brand-specific loading tools, like Oracle’s SQL*Loader utility. They just do traditional database inserts either via ODBC or JDBC.
Why SQL Loader is faster than insert?
SQL*Loader is the more efficient method. It gives you more control. You have an option do DIRECT load and NOLOGGING , which will reduce redo log generation, and when indexes have been disabled (as part of direct loading), the loading goes faster. Downside, is if load is interupted, indexes are left unusable .
How do I read a control file?
Answer: To see the controlfile contents, use these steps: SQL> alter database backup controlfile to trace; We can now view the controlfile contents (as a “create database” statement) by looking for the latest file in the user_dump_dest directory.
What is CTL file?
what is a . ctl file? The Microsoft Visual Studio 2010 software uses files appended with the . ctl format as developer files. These are stored in the CTL format that was created by Microsoft, and these CTL developer files are also called Visual Basic UserControl Object files.
What is CTL file in SQL?
SQL loader control file is used to load data from CSV or flat data file to Oracle tables. It usually has extension . ctl. In the control file, we define the structure for the data file and the target table in which we want to load data with some conditions.
What is CTL file in Oracle?
Every Oracle Database has a control file, which is a small binary file that records the physical structure of the database. … Names and locations of associated datafiles and redo log files. The timestamp of the database creation. The current log sequence number. Checkpoint information.
How do I skip a header in SQL Loader?
One can skip unwanted header records or continue an interrupted load (for example if you run out of space) by specifying the “SKIP=n” keyword. “n” specifies the number of logical rows to skip.
How do I ignore columns in SQL Loader?
1 Answer. Define the column you want to skip as FILLER. Keep in mind the order of the columns in the control file is typically the order they are in the datafile. If the name matches a column in the table, that’s where it will go.
What is optionally enclosed by in SQL Loader?
Indicates that the data should be enclosed by special characters. Can also be enclosed inTERMINATEDWithin characters.