Using BCP Utility for Fast Imports
By Tom Nonmacher
In the realm of SQL Server, the BCP (Bulk Copy Program) utility is a powerful tool that facilitates the fast import and export of large amounts of data. This command-line utility, which has been a part of SQL Server since its inception, and is available in SQL Server 2016, SQL Server 2017, Azure SQL, MySQL 5.7, and DB2 11.1, is especially useful when performance is a key consideration.
To understand how the BCP utility works, let's consider a simple example from SQL Server. Suppose you need to import data from a text file into a SQL Server table. The command for this would be as follows:
bcp MyDatabase.dbo.MyTable in MyTextFile.txt -c -T
In this command, the 'in' keyword indicates that data is being imported from 'MyTextFile.txt' into 'MyDatabase.dbo.MyTable'. The '-c' option specifies character data type and '-T' uses a trusted connection. This is a basic example and BCP utility offers many more options to handle complex scenarios.
The BCP utility isn't limited to SQL Server; it can also be used with MySQL. In MySQL, the 'LOAD DATA INFILE' command is equivalent to the BCP utility. Below is an example of a command that imports data from a text file into a MySQL table:
LOAD DATA INFILE 'MyTextFile.txt' INTO TABLE MyTable;
Similar to SQL Server and MySQL, DB2 also supports fast data imports using the IMPORT command. Here's a simple example:
IMPORT FROM MyTextFile.txt OF DEL INSERT INTO MyTable;
In all these examples, the data being imported must match the table schema. If the table already exists and you're trying to insert data that doesn't match, you'll encounter errors. Furthermore, while BCP utility is a powerful tool for handling large amounts of data, it's important to remember that it bypasses certain checks that are usually performed during data insertion, such as firing of triggers and enforcement of constraints, to ensure fast performance. Therefore, it's crucial to verify the integrity of data before and after using BCP.
To sum up, the BCP utility is a robust tool that every SQL Server professional should have in their toolkit. It enables the fast import and export of large amounts of data, making it an invaluable utility for tasks such as data migration, data warehousing and ETL operations. While the examples provided here are relatively simple, the BCP utility offers a host of options to handle more complex scenarios, making it an extremely flexible tool.