When dealing with large amounts of data, it is common to split the data into multiple files for easier management and processing. However, loading data from multiple files can be a challenging task. In this blog post, we will explore how to use SQL Loader - a powerful tool for loading data into an Oracle database - to load data from multiple files simultaneously.

Prerequisites

Before we begin, make sure you have the following prerequisites in place:

1. An Oracle database installed and running.
2. SQL Loader installed on your system.

Step 1: Prepare your data files

First, you need to split your data into multiple files. This can be done using various file splitting tools or by manually splitting the data. Each file should contain a subset of the data you want to load.

For example, let’s say we have a large file called data.csv that contains customer information. To split this file into multiple files, we can use a simple script or tool that splits the data based on a specified number of lines or records.

Step 2: Create a control file

A control file is a necessary component when using SQL Loader. It describes the format of the data being loaded and specifies the mapping between the data and the database table.

Create a control file (let’s call it data.ctl) using a text editor. Here is an example control file:

LOAD DATA
INFILE 'path/to/data1.csv'
INFILE 'path/to/data2.csv'
INFILE 'path/to/data3.csv'
...
APPEND
INTO TABLE customers
FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"'
(
  customer_id,
  customer_name,
  address,
  city,
  state
)

In the control file, specify the location of each data file using the INFILE clause. In this example, we are loading multiple files (data1.csv, data2.csv, data3.csv, etc.) using the INFILE clause.

Step 3: Execute the SQL Loader command

Once you have your control file ready, you can execute the SQL Loader command to load the data from multiple files into the Oracle database.

Open a command prompt or terminal window and execute the following command:

sqlldr username/password@database control=path/to/data.ctl

Replace username, password, and database with your Oracle database credentials.

SQL Loader will read the control file and load the data from all the specified files into the customers table, appending the data to any existing records.

Conclusion

In this blog post, we have explored how to use SQL Loader to load data from multiple files into an Oracle database. By splitting the data into multiple files and using a control file, you can efficiently load large amounts of data while maintaining ease of management and processing.

#SQLLoader #DataLoading