I make my first eshop using Prestashop and I'm not sure if is better use MyISAM or InnoDB. In eshop could be max about 3 000 items.
I think that most important for that question is how much items will be in eshop, but if I didn't write some other important information, please ask me.
This decision is dependent on read/write ratio. MYISAM uses table level level, so if a table is locked only one query can run on it hence MYISAM has serious performance issues. Also on prior version from 5.6 only MYISAM has support of FULLTEXT search. tables of MYISAM are really fast for SELECT queries and it takes less space on disk.
On the other hand, INNODB supports row-level locking hence concurrent select with insert is possible. It has support of doing ACID transactions hence each statement is atomic and durable in the event of crash.
So my decision is to use INNODB for application like eshop.
I would use InnoDB because it supports transactions and that's likely necessary for an eshop. For much more detailed information, check out the answers to this question:
MyISAM versus InnoDB
Related
I read that Innodb is better to use on a table that get a lot's of insert records simultaneously. My application gets about 50 records per seconds. So for these tables should I use Innodb, right?
In the other hand i have some tables that are only used for select, they get few updated or have few new insert. Is MyIsam faster for select ?
If it's the case, is it better to leave some table with MyIsam and some with Innodb or should i use all tables with the same engine ?
My application also searches a lot on the tables that i want to pass in Innodb. What should i do ?
you can check these:
Reasons to use MyISAM:
Tables are really fast for select-heavy loads
Table level locks limit their scalability for write intensive multi-user environments.
Smallest disk space consumption
Fulltext index
Merged and compressed tables.
Reasons to use InnoDB:
ACID transactions
Row level locking
Consistent reads – allows you to reach excellent read write concurrency.
Primary key clustering – gives excellent performance in some cases.
Foreign key support.
Both index and data pages can be cached.
Automatic crash recovery – in case MySQL shutdown was unclean InnoDB tables will still
recover to the consistent state- No check repair like MyISAM may require. All updates have to pass through transactional engine in
InnoDB, which often decreases - performance compared to
non-transactional storage engines.
quoted from here
and for the last part:
REMEMBER! It's OK to mix table types in the same database! In fact it's recommended and frequently required. However, it is important to note that if you are having performance issues when joining the two types, try converting one to the other and see if that fixes it. This issue does not happen often but it has been reported.
quoted from here
I hope that's enough :D
Yes you can, but I'd go with InnoDB only unless there is some serious performance bottleneck
same question on SO
MySQL forum
In short yes you can mix and match to your hearts content.
Keep the following in mind:
InnoDB is ACID complaint. Thus is you need any ACID features use InnoDB. MyISAM is does not support a lot of things like foreign key constraints for example.
Now speed is hard to quantify exactly. Depending on execution paths you might get very big or very small speed differences.
Test and check there is no right or wrong answer here.
I'm currently have a few tables with InnoDB Engine. 10-20 connections are constantly inserts data into those tables. I use MySQL RDS instance on AWS. Metric shows about 300 Write IOPS (counts/second). However, INSERT operations lock the table, and if someone want to perform a query like SELECT COUNT(*) FROM table; it could literally take a few hours for the first time before MySQL cache the result.
I'm not a DBA and my knowledge about DB are very limited. So the question is if I'll switch to MyISAM Engine will it help to improve the time of READ operations?
SELECT COUNT(*) without WHERE is bad query for InnoDB, as it does not cache the row count like MyISAM do. So if you have issue with this particular query, you have to cache the count somewhere - in a stats table for example.
After you remove this specific type of query, you can talk about InnoDB vs MyISAM read performance. Generally writes do not block reads in InnoDB - is uses MVCC for this. InnoDB performance however is very dependent of how much RAM you have set for the buffer pool.
InnoDB and MyISAM are very different in how they store data. You can always optimize for one of them and knowing the differences can help you in designing your application. Generally you can have as good performance for reading as in MyISAM in InnoDB tables - you just can use count without where clause, and you always should have a suitable index for where clauses, as in InnoDB table scan will be slower than in MyISAM.
I think you should stick with your current setup. InnoDB is supposed not to lock the table when inserting rows, since it uses the MVCC technique. On the other hand, MyISAM locks the entire table when new rows are inserted.
So, if you have many writes, you should stick with InnoDB.
Innodb is a better overall engine in general. There are some benchmarks out there that put read operations in myiasm a little ahead of innodb. However, if your site is big enough to notice this performance difference, you should be on innodb anyway because of all the other efficiencies. Innodb alone wins because of the row level locking instead if table level locking in myiasm when backing up your database.
I have a database with 48 tables and 45 of the tables are InnoDB.
I have 3 MyISAM tables which range in size from 200 records to 1.5Mil and also a 6.5Mil entries.
These 3 tables contain GEO Location information and are read only (never write - unless i was to update one - extremely infrequently).
I considered changing them to InnoDB to make the database 100% the same but then read the MYiSAM is faster. Note: I don't need any of the special INNODB functions - its just selects/joins... thats it.
Should I keep these MyISAM or change them to InnoDB?
thx
MyISAM used to be faster years ago, but if you use any reasonably current version of InnoDB, then InnoDB is faster for most workloads. Here's a performance comparison from way back in 2007 that shows InnoDB already matched or bettered MyISAM in all but a few types of queries.
http://www.mysqlperformanceblog.com/2007/01/08/innodb-vs-myisam-vs-falcon-benchmarks-part-1/
Since that test in 2007, InnoDB has continued to get better, whereas the MySQL developers have spent virtually no time improving MyISAM. It's dead, Jim.
The only cases where MyISAM may be faster is when doing full table-scans, and you should try to define indexes to avoid table-scans anyway.
InnoDB has been the default storage engine in MySQL since 5.5 (circa 2010). With each major version of MySQL, it becomes more clear that MyISAM is going away.
InnoDB has many benefits even if you don't use the explicit features like transactions or foreign keys. Try this:
Execute a long-running UPDATE against a MyISAM table.
Interrupt it partway through. How many rows have been changed? Some, but not all.
Repeat the same test with an InnoDB table. How many rows have been changed? Zero!
InnoDB supports atomic changes, so every SQL statement either succeeds completely, or else rolls back. You won't get partially-completed changes.
InnoDB also support crash recovery, so you won't lose data if mysqld ever crashes. MyISAM is renowned for corrupting tables during a crash.
InnoDB also caches data in RAM (the InnoDB buffer pool), whereas MyISAM relies on the filesystem cache to speed up data I/O. This makes some queries a lot faster in InnoDB if you have enough RAM.
Use MyISAM only if you don't care about your data.
No need to change In INNODB. As you say thay have lot of records SO thay are faster as MYISAM
MyISAM in most cases will be faster than InnoDB for run of the mill sort of work. Selecting, updating and inserting are all very speedy under normal circumstances.
I wouldn't bother changing it. I was just researching the same thing and came across this useful post: http://www.kavoir.com/2009/09/mysql-engines-innodb-vs-myisam-a-comparison-of-pros-and-cons.html
The main reason you'd want Innodb would be for data integrity and to avoid locking the entire table on inserts. But if you're not doing a lot of inserts and these are not high traffic tables, then why make the change?
No change is necessary, i am working on similar project where the database is going to be used for read-only and Myisam is the best option for it.
In addition you can even use sphinx if you want faster reads.
hope this helps.
Sometimes I got asked on some interviews: what benefits does InnoDB have against MyISAM and when MyISAM is better than InnoDB? It's all clear about the first part of question: InnoDB is transaction compliant, row-level blocking instead of table-level blocking, foreign key support and some others, these points just came to mind immidiately.
But when MyISAM is really better than InnoDB?
MyISAM is better than InnoDB when you don't need those advanced features and storage speed is more important than other concerns. MyISAM also allows full-text searches to be performed inside the database engine itself, instead of needing to query results and then search them as an array or whatever in your application.
InnoDB is a reasonable choice if you need to store data with a high degree of fidelity with complicated interactions and relationships. MyISAM is a reasonable choice if you need to save or load a large number of records in a small amount of time.
I wouldn't recommend using MyISAM for data that matters. It's great for logging or comments fields or anything where you don't particularly care if a record vanishes into the twisting nether. InnoDB is good for when you care about your data, don't need fast searches and have to use MySQL.
It's also worth mentioning that InnoDB supports row-level locking, while MyISAM only supports table-level locking - which is to say that for many common situations, InnoDB can be dramatically faster due to more queries executing in parallel.
The bottom line: Use InnoDB unless you absolutely have to use MyISAM. Alternatively, develop against PostgreSQL and get the best of both.
MyISAM doesn't support transactions (and the other things mentioned) so it can work faster. MyISAM is a way to achieve higher performance in those situations when you do not need these features.
MyISAM supports full text, as mentioned, but also supports the MERGE table type. This is handy when you have a large table and would like to "swap" out/archive parts of it periodically. Think about a logging or report data that you want to keep the last quarter and/or year. MyISAM handles large amounts of data like this better, when you are mainly inserting and rarely updating or deleting.
InnoDB performance drops pretty quickly and dramatically once you can't fit the indexes in memory. If your primary key is not going to be a number (i.e. auto increment), then you may want to rethink using InnoDB. The primary key is replicated for every index on an InnoDB table. So if you have a large primary key and a few other indexes, your InnoDB table will get very large very quick.
There are a few features that MySQL only has implemented for MyISAM (such as native fulltext indexing).
That said, InnoDB is still typically better for most production apps.
Also: Full-text search in mySQL is only supported in myISAM tables.
MyISAM has a very simple structure, when compared with InnoDB. There is no row versioning, there's one file per table and rows are stored sequentially. However, while it supports concurrent inserts (SELECTs and 1 INSERT can run together), it also has table-level locks (if there are 2 INSERTs on the same table, 1 has to wait). Also, UPDATEs and DELETEs are slow because of the structure of the data files.
MyISAM doesn't support transactions or foreign keys.
Generally, MyISAM should be better if you work on general trends (so you don't care about the correctness of individual rows) and data is updated by night or never. Also, it allows to move individual tables from one server to another, via the filesystem.
InnoDB supports very well concurrency and transactions. Has a decent support for fulltext and an almost-decent support for foreign keys.
I heard this today during interview for java developer. I had to list some advantages of MyISAM over InnoDB and why it's still being widely used. And they were waiting to hear from me the answer as the title of this question.
As I understand from their own answer: MyISAM doesn't have foreign keys and DB can be easily clustered (one table per server for example). But why can't we simply create InnoDB tables without foreign keys? This explaination sounds strange to me..
There is no silver bullet answer here. You need to know the pros and cons of each before you make a decision on which one you use for any particular application.
InnoDB:
supports FK's
supports transactions
uses a large memory buffer for operation
supports row level locking
But has a much higher maintenance cost -- you really need to tune your memory usage, configure your table files, etc.
MyISAM:
has a bunch of special column features that InnoDB doesn't, like:
full text indexes
spatial columns (I'm pretty sure this doesn't work with InnoDB)
Very fast for primary read/append use cases (table locks for updates, deletes, but not for inserts)
Also typically has faster inserts
caches indexes in memory (key buffer), but relies on the OS to buffer the actual data pages
For example, I'd use InnoDB for things like ecommerce, user databases or anything that I want to use transactions in.
For data warehouses, logging, reporting, etc I'd probably use MyISAM.
I had to list some advantages of MyISAM over InnoDB
FULLTEXT search
...
no, that's it.
(OK, there are some cases where MyISAM is faster than InnoDB, but rarely enough that it's worth putting up with the lack of ACID-compliance. Today the main reason for doing anything with MyISAM is to get fulltext search which is sadly not supported in InnoDB.)
I am not sure if this is no longer true MyISAM is faster than InnoDB for reads.
Also, MyISAM tables are stored in separate files and (from what I can remember) you can actually transport those files to another MySQL database and is easier to backup.
By default InnoDB databases are stored in one huge glob on the file system.
As for why it is still being widely used, I always figured it was because it is the default option. Personally, I still believe that the advantages of InnoDB triumphs MyISAM and MyISAM also has problems with data integrity from my experience.
You certainly could create InnoDB tables without foreign keys, but that is cutting out one of the main advantages of it: referential integrity.
However, since MyISAM isn't built with the intent of referential integrity table keys can be stored differently, and perhaps more efficiently.
There are also some differences in locking and access. InnoDB supports row level locking, whereas MyISAM only supports table-level locking. Depending on the queries you're performing (SELECTS versus INSERTS/UPDATES) this can have a noticeable effect on performance.
You prolly need to read up on the Mysql Peformance blog.