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Rechercher dans le manuel MySQL
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https://dev.mysql.com/mysql-nutshell.html
As of MySQL 8.0.13, the TempTable storage engine supports storage of binary large object (BLOB) type columns. This enhancement improves performance for queries that use temporary tables containing BLOB data. Previously, temporary tables that ...
https://dev.mysql.com/glossary.html
off-page column A column containing variable-length data (such as BLOB and VARCHAR) that is too long to fit on a B-tree page. overflow page Separately allocated disk pages that hold variable-length columns (such as BLOB and VARCHAR) that are too ...
https://dev.mysql.com/mysql-cluster-option-tables.html
Com_show_ndb_status: Count of SHOW NDB STATUS statements Handler_discover: Number of times that tables have been discovered ndb-batch-size: Size (in bytes) to use for NDB transaction batches ndb-blob-read-batch-bytes: Specifies size in bytes that ...
https://dev.mysql.com/mysql-cluster-programs-ndb-desc.html
Table 22.341 Command-line options for the ndb_desc program Format Description Added, Deprecated, or Removed --blob-info, -b Include partition information for BLOB tables in output. All NDB 8.0 releases --unqualified, -u Use unqualified table names ... ndb_desc provides a detailed description of one or more NDB ...
https://dev.mysql.com/data-type-defaults.html
The BLOB, TEXT, GEOMETRY, and JSON data types cannot be assigned a default value. Data type specifications can have explicit or implicit default values. A DEFAULT value clause in a data type specification explicitly indicates a default value for a ...
https://dev.mysql.com/json.html
The space required to store a JSON document is roughly the same as for LONGBLOB or LONGTEXT; see Section 11.8, “Data Type Storage Requirements”, for more information. BLOB BIT OPAQUE DATETIME TIME DATE BOOLEAN ARRAY OBJECT STRING INTEGER, DOUBLE ...The JSON data type provides these advantages over storing JSON-format strings in a string column: Automatic validation of JSON documents stored in JSON ...
https://dev.mysql.com/column-indexes.html
When you index a BLOB or TEXT column, you must specify a prefix length for the index. For example: CREATE TABLE test (blob_col BLOB, INDEX(blob_col(10))); Prefixes can be up to 767 bytes long for InnoDB tables that use the REDUNDANT or COMPACT row ... The most common type of index involves a single column, storing copies of the values from that column in a data structure, allowing fast lookups for the rows with the corresponding column ...
https://dev.mysql.com/mysql-fetch-field.html
If you've called mysql_query() to perform a SELECT on a table but have not called mysql_store_result(), MySQL returns the default blob length (8KB) if you call mysql_fetch_field() to ask for the length of a BLOB field. (The 8KB size is chosen ...
https://dev.mysql.com/mysql-cluster-limitations-syntax.html
You cannot create indexes on NDB table columns that use any of the TEXT or BLOB data types. The NDB API has no special provision for working with JSON data, which it views simply as BLOB data. Some SQL statements relating to certain MySQL features ...
https://dev.mysql.com/create-index.html
Additionally, BLOB and TEXT columns can be indexed only for InnoDB, MyISAM, and BLACKHOLE tables. However, prefix lengths for index specifications in CREATE TABLE, ALTER TABLE, and CREATE INDEX statements are interpreted as number of characters for ... CREATE [UNIQUE | FULLTEXT | SPATIAL] INDEX index_name [index_type] ON tbl_name (key_part,...) [index_option] [algorithm_option | lock_option] ...
Document created the 26/06/2006, last modified the 26/10/2018
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