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https://dev.mysql.com/doc/internals/en/the-myi-file.html
A .MYI file for a MyISAM table contains the table's indexes. The .MYI file has two parts: the header information and the key values. So the next sub-sections will be "The .MYI Header" and "The .MYI Key Values". The .MYI Header A .MYI file begins ...
https://dev.mysql.com/doc/refman/8.4/en/aggregate-functions.html
They are often used with a GROUP BY clause to group values into subsets. For a faster count, create a counter table and let your application update it according to the inserts and deletes it does. To specify a separator explicitly, use SEPARATOR ...
https://dev.mysql.com/doc/refman/8.4/en/charset-unicode-utf16.html
For example, since U+F8FF is the Apple Logo, this is legal: INSERT INTO t (utf16_column)VALUES (0xf8ff); /* legal */ Such characters cannot be expected to mean the same thing to everyone. Because utf16 supports surrogates and ucs2 does not, there is ... The utf16 character set is the ucs2 character set with an extension that enables encoding of supplementary characters: For a BMP character, utf16 and ucs2 have identical storage characteristics: same code values, same encoding, same ...
https://dev.mysql.com/doc/refman/8.4/en/create-table-secondary-indexes.html
There are additional write costs to consider when using a secondary index on a virtual column due to computation performed when materializing virtual column values in secondary index records during INSERT and UPDATE operations. A secondary index ...
https://dev.mysql.com/doc/refman/8.4/en/create-table-select.html
This follows the same rules as with VALUES; all columns of the source table and their names in the source table are always inserted into the new table. SELECT, if IF NOT EXISTS is given and the target table exists, nothing is inserted into the ...To ... You can create one table from another by adding a SELECT statement at the end of the CREATE TABLE statement: CREATE TABLE new_tbl [AS] SELECT * FROM orig_tbl; MySQL creates new columns for all elements in the ...
https://dev.mysql.com/doc/refman/8.4/en/extensions-to-ansi.html
The LOW_PRIORITY clause of the INSERT, REPLACE, DELETE, and UPDATE statements. For example: mysql> SELECT col1=1 AND col2=2 FROM my_table; The LAST_INSERT_ID() function returns the most recent AUTO_INCREMENT value. MySQL Server supports some ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-and-mysql-replication.html
It is possible to use replication in a way where the storage engine on the replica is not the same as the storage engine on the source. For example, you can replicate modifications to an InnoDB table on the source to a MyISAM table on the replica.
https://dev.mysql.com/doc/refman/8.4/en/memory-storage-engine.html
Deleted rows are put in a linked list and are reused when you insert new data into the table. For example, you can put statements such as INSERT INTO ... MEMORY tables also have none of the problems commonly associated with deletes plus inserts in ... The MEMORY storage engine (formerly known as HEAP) creates special-purpose tables with contents that are stored in ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-replication-issues.html
If this occurs, it is entirely possible for new data to be inserted into the source cluster without being recorded in the source SQL node's binary log. In the event of a node failure, errors in replication of NDB tables without primary keys can ...
https://dev.mysql.com/doc/refman/8.4/en/precision-math-rounding.html
This section discusses precision math rounding for the ROUND() function and for inserts into columns with exact-value types (DECIMAL and integer). The ROUND() function rounds differently depending on whether its argument is exact or approximate: ...