When working with large datasets, it is common to use SQL Loader to load data into Oracle databases quickly. SQL Loader is a command-line tool that allows you to load data from external files into Oracle tables.
While loading data, it is crucial to capture any errors or exceptions that may occur. SQL Loader provides the ability to generate log files and error reports, which can be incredibly helpful for troubleshooting and debugging purposes.
In this blog post, we will explore how to generate log files and error reports with SQL Loader and how to interpret the information provided in these files.
Table of Contents
Generating log files
When running SQL Loader, you can specify a log file to capture the execution details. The log file contains information such as the number of rows processed, the number of rows successfully loaded, and any rejected rows along with the reason for rejection.
To generate a log file, you can use the LOG parameter followed by the desired file name. Here’s an example:
sqlldr username/password@tns_alias control=data.ctl log=data.log
In this example, data.log is the name of the log file that will be generated during the data loading process.
Generating error reports
In addition to the log file, SQL Loader can also generate an error report that lists all the rejected records and the reason for their rejection. The error report provides useful information to identify and fix any issues with the data being loaded.
To generate an error report, you need to specify the bad parameter followed by the file name where you want the report to be saved. Here’s an example:
sqlldr username/password@tns_alias control=data.ctl log=data.log bad=data.bad
In this example, data.bad is the name of the file where the error report will be generated.
Interpreting log files and error reports
Once you have generated the log file and the error report, you can open them with a text editor to analyze the information.
The log file will provide an overview of the data loading process, including the number of rows processed, the number of rows successfully loaded, and any rejected rows. It also provides timing information and summary statistics.
The error report, on the other hand, will list all the rejected records and the reason for their rejection. Each rejected record is accompanied by the error message, which can help identify the issue and take appropriate corrective actions.
When interpreting the log files and error reports, pay attention to any specific error codes or messages that indicate the nature of the problem. For example, constraints violations, data type mismatches, or formatting errors.
Conclusion
Generating log files and error reports with SQL Loader is crucial for troubleshooting and debugging data loading processes. These files provide valuable information about the execution details, rejected records, and error messages.
By utilizing the log files and error reports generated by SQL Loader, you can quickly identify issues with the data and take appropriate corrective actions. This helps ensure the integrity and accuracy of the loaded data.
Remember to always review and analyze the log files and error reports when working with SQL Loader to streamline your data loading processes and maintain data quality.
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