Скачать или смотреть Updating Millions of Rows in SQL (Quick & Easy)

In this sql tutorial we'll walk you through your options when updating millions of rows in a database management system.

Saying that updating millions or even billions of records in a SQL database is hard is an understatement.
The task can become daunting even for the most experienced DBAs on the planet and big data-related interview questions are some of the most frequent interview questions in the sql interview questions and answers field. Don't fret - this video will help you out.

1) Optimizing UPDATEs:
The first and the most obvious option is to optimize your UPDATE SQL queries.
To make your UPDATE SQL queries faster, remove SQL indexes from your column, partitions from your table, or delay SQL UPDATE queries and then do many updates in a row later.
We've already made a couple of sql indexes explained videos, so if you're interested in sql indexes, make sure to watch them.

2) Filtering out unnecessary data from your MySQL server or any other SQL database:
Another way to update big data sets faster is to employ the WHERE clause to filter out unnecessary data from your MySQL server or any other database management system.
To do this, employ the WHERE clause - the WHERE SQL query lets us update only a subset of the data, thus making our SQL queries faster.

3) The LIMIT clause:
Also consider updating data in batches with a LIMIT SQL query. Update the first 100,000 records, then update records starting from the 100,000th row, and so on. Use this SQL query:
UPDATE your_table SET your_column = 'Value' LIMIT 0,100000;
UPDATE your_table SET your_column = 'Value' LIMIT 100000,200000;
...

4) The DEFAULT clause:
If you want your entire table to be updated, you can also employ the DEFAULT clause upon table creation - take a backup of your table, add a DEFAULT clause to the column you need to update, then re-import the data into your mysql server. After doing that, you will see that your column has the desired values.

5) The LOAD DATA INFILE SQL query:
And last but not least, you can also make use of LOAD DATA INFILE. LOAD DATA INFILE inserts data, but without the overhead of INSERT SQL queries, so that's an alternative to DEFAULT - before inserting data, specify a column with a value in your file, then use the FIELDS TERMINATED BY clause, and you should be good to go.

We hope that you've enjoyed this SQL tutorial for beginners - do let us know whether you want us to make another SQL tutorial on the MySQL workbench, SQL indexes, MySQL database performance optimization, or a SQL crash course. Enjoy this sql tutorial - we hope it will answer some of the sql interview questions you may be asked in your next database interview.

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