Limitations in Azure Database for MySQL
The following sections describe capacity, storage engine support, privilege support, data manipulation statement support, and functional limits in the database service. Also see general limitations applicable to the MySQL database engine.
Service tier maximums
Azure Database for MySQL has multiple service tiers to choose from when creating a server. For more information, see Azure Database for MySQL pricing tiers.
There is a maximum number of connections, Compute Units, and storage in each service tier, as follows:
|Pricing Tier||Compute Generation||vCore(s)||Max Connections|
|General Purpose||Gen 4||2||300|
|General Purpose||Gen 4||4||625|
|General Purpose||Gen 4||8||1250|
|General Purpose||Gen 4||16||2500|
|General Purpose||Gen 4||32||5000|
|General Purpose||Gen 5||2||300|
|General Purpose||Gen 5||4||625|
|General Purpose||Gen 5||8||1250|
|General Purpose||Gen 5||16||2500|
|General Purpose||Gen 5||32||5000|
|Memory Optimized||Gen 5||2||600|
|Memory Optimized||Gen 5||4||1250|
|Memory Optimized||Gen 5||8||2500|
|Memory Optimized||Gen 5||16||5000|
When too many connections are reached, you may receive the following error:
ERROR 1040 (08004): Too many connections
Storage engine support
- DBA role: Many server parameters and settings can inadvertently degrade server performance or negate ACID properties of the DBMS. As such, to maintain the service integrity and SLA at a product level, this service does not expose the DBA role. The default user account, which is constructed when a new database instance is created, allows that user to perform most of DDL and DML statements in the managed database instance.
- SUPER privilege: Similarly SUPER privilege is also restricted.
Data manipulation statement support
- LOAD DATA INFILE - Supported, but it must specify the [LOCAL] parameter that is directed to a UNC path (Azure storage mounted through XSMB).
- SELECT ... INTO OUTFILE
- Dynamic scaling of servers across pricing tiers is currently not supported. That is, switching between Basic, General Purpose, and Memory Optimized pricing tiers.
- Decreasing server storage size is not supported.
Server version upgrades
- Automated migration between major database engine versions is currently not supported.
- Restoring to different service tier and/or Compute Units and Storage size is not allowed.
- Restoring a deleted server is not supported.
- Dynamically moving pre-created servers across subscription and resource group is currently not supported.
Current known issues
- MySQL server instance displays the wrong server version after connection is established. To get the correct server instance versioning, use select version(); command at the MySQL prompt.