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https://dev.mysql.com/doc/refman/8.4/en/custom-benchmarks.html
After fixing one bottleneck (or by replacing it with a “dummy” module), you can proceed to identify the next bottleneck. Most of the time, these problems would be much easier to fix if the systems were not already in production. Benchmark your ...
https://dev.mysql.com/doc/refman/8.4/en/data-types.html
For floating-point and fixed-point types, M is the total number of digits that can be stored (the precision). D applies to floating-point and fixed-point types and indicates the number of digits following the decimal point (the scale). MySQL ...
https://dev.mysql.com/doc/refman/8.4/en/dynamic-format.html
If you have fixed-length columns that you access or change frequently in a table that also contains some variable-length columns, it might be a good idea to move the variable-length columns to other tables just to avoid fragmentation. Much less disk ... Dynamic storage format is used if a MyISAM table contains any variable-length columns (VARCHAR, VARBINARY, BLOB, or TEXT), or if the table was created with the ROW_FORMAT=DYNAMIC table ...
https://dev.mysql.com/doc/refman/8.4/en/faqs-mysql-cluster.html
However, if your application requires “five nines” availability, you should use fixed (numeric) IP addresses, since making communication between Cluster hosts dependent on services such as DNS and DHCP introduces additional potential points of ... In the following section, we answer questions that are frequently asked about MySQL NDB Cluster and the NDB storage ...
https://dev.mysql.com/doc/refman/8.4/en/group-replication-frequently-asked-questions.html
You need to find out why a member is lagging behind and fix that or remove the member from the group. Alternatively, another way of fixing the issue specifically in Group Replication is to issue a STOP GROUP_REPLICATION statement and then a START ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-doublewrite-buffer.html
With this setting, the doublewrite buffer is fully enabled, with database page content written to the doublewrite buffer where it is accessed during recovery to fix incomplete page writes. Database page content is not written to the doublewrite ...
https://dev.mysql.com/doc/refman/8.4/en/memory-storage-engine.html
Variable-length types such as VARCHAR are stored using a fixed length. The MEMORY storage engine (formerly known as HEAP) creates special-purpose tables with contents that are stored in memory. Because the data is vulnerable to crashes, hardware ...
https://dev.mysql.com/doc/refman/8.4/en/myisam-table-formats.html
Two of them, fixed and dynamic format, are chosen automatically depending on the type of columns you are using. When you use CREATE TABLE or ALTER TABLE for a table that has no BLOB or TEXT columns, you can force the table format to FIXED or DYNAMIC ...The third, compressed format, can be created only with the myisampack utility (see Section 6.6.6, “myisampack — Generate Compressed, Read-Only MyISAM ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-limitations-syntax.html
There are no prefix indexes; only entire columns can be indexed. A partial fix for this issue improved the error used internally to work in most cases; however, it remains possible for this situation to occur in the event that the parent index is a ... Some SQL statements relating to certain MySQL features produce errors when used with NDB tables, as described in the following list: Temporary ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-ndbd-definition.html
For those parameters affecting memory usage or buffer sizes, it is possible to use K, M, or G as a suffix to indicate units of 1024, 1024×1024, or 1024×1024×1024. Variable-length records use a fixed-size part with an extra overhead of 4 bytes to ... The [ndbd] and [ndbd default] sections are used to configure the behavior of the cluster's data ...