Importing Data Using MySQL and Arctype
In this blog, we will look through the options you have when it comes to importing data into your MySQL instances.
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If you are a developer or database administrator that wants to load the data into your databases quickly, you probably already know that you have quite a few options, at least as far as MySQL is concerned. In this blog, we will look through the options you have when it comes to importing data into your MySQL instances.
What Options Are There?
First of all, when it comes to importing data into MySQL, you have a couple of options to import data:
- One can use
INSERT INTOand specify a table name along with the columns and data one needs to import into a given database instance.
- One can also use
LOAD DATA INFILEand specify a specific file where he or she wants to load data into a given table.
Now we could tell you that "no,
LOAD DATA INFILE is not the only option when importing data into MySQL or MariaDB-based instances" and leave it at that, however, that's not what you're here for - you're here to know the best mechanism to use for importing your data into MySQL-based instances.
By now you know that
LOAD DATA INFILE and
INSERT INTO are your only options - however, you might also know that we have covered some of the functionalities provided by
LOAD DATA INFILE in an earlier blog post of ours, so you might wonder why we are writing another one. Well, we haven't covered everything!
For example, we told you that
LOAD DATA INFILE is faster, and it is. But once you have the need to quickly import data into your database instances, you have a couple of other options too. For example, you can use
COMMIT statements like so:
Running queries in the above-specified fashion would help your database perform better when inserting data because
COMMIT statements save the current state of the database. In other words, turning
autocommit to a value of 0, importing your data, and committing then might be a better option in terms of importing data in MySQL because you would only save modifications to disk when you want to and relieve MySQL (or MariaDB) of such hassles. Also, consider setting
unique_checks to 0 and
foreign_key_checks to 0 as well: setting these parameters to off (0) should improve your database performance as well.
Another quick way to import data into MySQL if you are running the MyISAM storage engine would be to just simply copy the
.MYI files over into a given folder on a different database server. Here's a caveat though - you should only do this with MyISAM because InnoDB works differently. Never try such an approach on it unless you are fully aware of the consequences.
You can read this blog post about InnoDB vs. big data to learn more, but essentially, InnoDB has one core file - ibdata1 - that is central to its performance. Simply copying over files like this would do more harm than good because the tablespace ID in the ibdata1 would not match the tablespace ID in the database files that were copied over to a new server.
Another quick way to speed up a given data import is to lock the table while importing. Run a
LOCK TABLES query before importing your data and
UNLOCK TABLES when you're done, and you should be good to go. Such an approach is recommended if you have a situation where you might find yourself required to prevent certain sessions from modifying tables.
You can also use the bulk importing functionality provided by
INSERT statements as well.
INSERT INTO arctype (demo_column) VALUES ('demo'), ('demo'); would be inserted faster than ordinary
However, these are not the only options you can employ. If you are using MyISAM (you shouldn't be, but if you find yourself forced to use such a storage engine...) you might also want to think about increasing the value of
bulk_insert_buffer_size. According to MySQL, the variable limits the size of the cache tree in bytes per a single thread, so that should help if you find yourself importing quite a lot of data when working with MyISAM as well.
A consideration: the secure_file_priv variable
secure_file_priv variable is heavily associated with bulk importing of data inside of your database instances. In prior posts, we said that
LOAD DATA INFILE is significantly faster than
INSERT statements due to the fact that it comes with many so-called "bells and whistles" unique to itself. Part of that magic is
load_data_infile. The variable usually resides in your
my.cnf file (which itself is located in your
/var/bin/mysql directory) and looks like so (the following example refers to the variable being used in Windows environments):
This variable, simply put, puts a restraint on which directories can be used to load data into your MySQL database instance. In other words, once you run a
LOAD DATA INFILE query and the file you load into your database instance does not reside in this directory, MySQL will come back with an error like so:
To overcome this error, you either need to remove the
--secure-file-priv setting from your
my.cnf file, or load your data from a directory specified in the value of the variable. Once you do so, your data should be loaded in (and exported) without any kinds of issues!
Aside from loading data into your MySQL database instances using
LOAD DATA INFILE and making use of this privilege, the value of such a variable might also be relevant when exporting data out of MySQL using
SELECT ... INTO OUTFILE. this variable can also be used to disable import and export operations using
LOAD DATA INFILE and
SELECT ... INTO OUTFILE: simply set this variable to
NULL in such a case. In general, though, you can also run a query like
SHOW QUERY VARIABLES LIKE 'secure_file_priv' or
SELECT @@secure_file_priv in order to observe the name of the directory that this variable is set to.
Time to Import Some Data!
So, you're ready to import some data. Can you just use
INSERT queries and insert all of the rows one by one? Or perhaps you would use bulk inserting capabilities provided by
Technically, yes - you can do that. You can insert your rows from a CSV file by copying them over to
INSERT statements, and then running them one by one, but that would take quite a lot of time, also you would need to make sure you are copying over the correct values of rows from the CSV file into your
INSERT statement, etc. - that would be quite a hassle!
Thankfully, there are tools that can assist you in performing such tasks. Some of those tools are SQL clients. For example, the SQL client developed by Arctype can help you edit your tables like spreadsheets where you select any cell you want to edit, and delete rows by simply clicking delete, etc.
However, Arctype has another feature that should be more relevant to the scope of this article - Arctype also lets you import CSV files into your database instances. Let's see how to do that!
Go ahead and launch Arctype. Towards the right-hand side of your table and above the structure of it, you will find three horizontal dots. Click on them:
These dots denote the options available for you to use: you can either create a table or refresh them, or you can also import the contents of a given CSV file to your table. Click on Import CSV and select the file you want to import:
Arctype will provide you with some information regarding your file, and it will provide the first five rows that your CSV file contains. Once you're satisfied with the outputs you see, it's time to import your data - go ahead and click Accept:
Once you click accept, you will be able to define the columns of your table that you want to import your data to, you will be able to create a new table or elect to upload your data into an existing table.
Once you're satisfied with what you see on the screen, go ahead and click Import CSV to import your file: your data should now exist inside of your tables! That's it - it's really that simple.
Sometimes when your data is too long to be imported, and you might face some errors like the one above (in that case, Arctype will import all of the rows leading up to the error), but generally, the import process should go smoothly
The Bottom Line
When you find yourself required to quickly import data into your MySQL instances,
LOAD DATA INFILE is far from your only option. You can also use bulk inserting capabilities provided by
INSERT statements, modify MySQL's functionality in such a way that commits only after the data is fully loaded into your database tables, and only load data into specific columns using
LOAD DATA INFILE as well.
We hope you stick around the blog since we have a lot more content prepared for you - this blog covers databases, security, and general advice for developers, so you will certainly find what you are looking for. And, if you want to play around with what you've learned so far, Arctype is the perfect tool with which to do so.
Published at DZone with permission of Everett Berry. See the original article here.
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