Search Results
https://dev.mysql.com/doc/refman/8.4/en/binary-varbinary.html
The BINARY and VARBINARY types are similar to CHAR and VARCHAR, except that they store binary strings rather than nonbinary strings. Instead, it causes the binary (_bin) collation for the column character set (or the table default character set if ...This means they have the binary character set and collation, and comparison and sorting are based on the numeric values of the bytes in the ...
https://dev.mysql.com/doc/refman/8.4/en/column-count-limit.html
Functional key parts (see Section 15.1.15, “CREATE INDEX Statement”) are implemented as hidden virtual generated stored columns, so each functional key part in a table index counts against the table total column limit. BLOB and TEXT columns only ... This section describes limits on the number of columns in tables and the size of individual ...
https://dev.mysql.com/doc/refman/8.4/en/data-dictionary-usage-differences.html
Examples: ANALYZE TABLE fails because it updates table statistics, which are stored in the data dictionary. ALTER TABLE tbl_name ENGINE=engine_name fails because it updates the storage engine designation, which is stored in the data dictionary. Use ...
https://dev.mysql.com/doc/refman/8.4/en/enum.html
When retrieved, values stored into an ENUM column are displayed using the lettercase that was used in the column definition. If you store a number into an ENUM column, the number is treated as the index into the possible values, and the value stored ... An ENUM is a string object with a value chosen from a list of permitted values that are enumerated explicitly in the column specification at table creation ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-fulltext-index.html
Inverted indexes store a list of words, and for each word, a list of documents that the word appears in. To support proximity search, position information for each word is also stored, as a byte offset. mysql> SELECT index_id, name, table_id, space ... Full-text indexes are created on text-based columns (CHAR, VARCHAR, or TEXT columns) to speed up queries and DML operations on data contained within those ...
https://dev.mysql.com/doc/refman/8.4/en/memory-storage-engine.html
The MEMORY storage engine (formerly known as HEAP) creates special-purpose tables with contents that are stored in memory. Variable-length types such as VARCHAR are stored using a fixed length. CREATE TABLE t (i INT) ENGINE = MEMORY; As indicated ...Because the data is vulnerable to crashes, hardware issues, or power outages, only use these tables as temporary work areas or read-only caches for data pulled from other ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-ndbinfo-memory-per-fragment.html
These memory pages are managed as listed here: Fixed-size pages: These store the fixed-size parts of rows stored in a given fragment. Variable-sized pages: These store variable-sized parts for rows in the fragment. Hash index pages: These are ...
https://dev.mysql.com/doc/refman/8.4/en/numeric-type-syntax.html
Display width is unrelated to the range of values a type can store, as described in Section 13.1.6, “Numeric Type Attributes”. For floating-point and fixed-point data types, M is the total number of digits that can be stored. For example, ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-management-range-list.html
It is very important to remember that, when you drop a partition, you also delete all the data that was stored in that partition. DROP PARTITION with ALGORITHM=INPLACE deletes data stored in the partition and drops the partition. However, as ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-overview.html
In effect, different portions of a table are stored as separate tables in different locations. In the case of RANGE, LIST, and [LINEAR] HASH partitioning, the value of the partitioning column is passed to the partitioning function, which returns an ... This section provides a conceptual overview of partitioning in MySQL ...