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https://dev.mysql.com/doc/refman/8.0/en/optimizing-memory-tables.html

For best performance with MEMORY tables, examine the kinds of queries against each table, and specify the type to use for each associated index, either a B-tree index or a hash index. B-tree indexes are fast for queries that do greater-than or ...

10.3.5 Column Indexes

https://dev.mysql.com/doc/refman/8.0/en/column-indexes.html

The B-tree data structure lets the index quickly find a specific value, a set of values, or a range of values, corresponding to operators such as =, >, ≤, BETWEEN, IN, and so on, in a WHERE clause. Other storage engines use B-trees for indexing ...

10.10.2 The MyISAM Key Cache

https://dev.mysql.com/doc/refman/8.0/en/myisam-key-cache.html

Usually the size of an index block is equal to the size of nodes of the index B-tree. To minimize disk I/O, the MyISAM storage engine exploits a strategy that is used by many database management systems. It employs a cache mechanism to keep the ...

10.3.1 How MySQL Uses Indexes

https://dev.mysql.com/doc/refman/8.0/en/mysql-indexes.html

Most MySQL indexes (PRIMARY KEY, UNIQUE, INDEX, and FULLTEXT) are stored in B-trees. Characteristics specific to hash indexes (as used in MEMORY tables) are described in Section 10.3.9, “Comparison of B-Tree and Hash Indexes”. Indexes are used ...

17.9.1.3 Tuning Compression for InnoDB Tables

https://dev.mysql.com/doc/refman/8.0/en/innodb-compression-tuning.html

The compressed page size should always be bigger than the maximum record size, or operations may fail as noted in Compression of B-Tree Pages. If the compressed page size is set too small, inserts or updates may require time-consuming recompression, ... Most often, the internal optimizations described in InnoDB Data Storage and Compression ensure that the system runs well with compressed ...

17.9.1.4 Monitoring InnoDB Table Compression at Runtime

https://dev.mysql.com/doc/refman/8.0/en/innodb-compression-tuning-monitoring.html

Since MySQL splits B-tree nodes when they are too full to contain the compressed data following a modification, compare the number of “successful” compression operations with the number of such operations overall. If the ratio is low, then MySQL ... Overall application performance, CPU and I/O utilization and the size of disk files are good indicators of how effective compression is for your ...

17.5.3 Adaptive Hash Index

https://dev.mysql.com/doc/refman/8.0/en/innodb-adaptive-hash.html

The prefix can be any length, and it may be that only some values in the B-tree appear in the hash index. For information about the performance characteristics of hash indexes, see Section 10.3.9, “Comparison of B-Tree and Hash Indexes”. The ...

28.4.20 The INFORMATION_SCHEMA INNODB_INDEXES Table

https://dev.mysql.com/doc/refman/8.0/en/information-schema-innodb-indexes-table.html

For full-text indexes, the PAGE_NO column is unused and set to -1 (FIL_NULL) because the full-text index is laid out in several B-trees (auxiliary tables). For related usage information and examples, see Section 17.15.3, “InnoDB INFORMATION_SCHEMA ...

17.21.3 Forcing InnoDB Recovery

https://dev.mysql.com/doc/refman/8.0/en/forcing-innodb-recovery.html

A value of 6 is considered drastic because database pages are left in an obsolete state, which in turn may introduce more corruption into B-trees and other database structures. Leaves database pages in an obsolete state, which in turn may introduce ... To investigate database page corruption, you might dump your tables from the database with SELECT ...

13.4.10 Creating Spatial Indexes

https://dev.mysql.com/doc/refman/8.0/en/creating-spatial-indexes.html

For storage engines that support nonspatial indexing of spatial columns, the engine creates a B-tree index. A B-tree index on spatial values is useful for exact-value lookups, but not for range scans. For InnoDB and MyISAM tables, MySQL can create ...

Displaying 11 to 20 of 39 total results