Search Results
https://dev.mysql.com/doc/mysql-ai/9.4/en/mys-ai-aml-explanations-ml-explain-row.html
ML_EXPLAIN_ROW explains predictions for one or more rows of unlabeled data. After training and loading the model, you can generate prediction explanations for one or more rows. Generating a Row Prediction Explanation with the Default Permutation ...
https://dev.mysql.com/doc/refman/8.4/en/row-constructor-optimization.html
However, the row constructor itself does not cover an index prefix, with the result that the optimizer uses only c1 (key_len=4, the size of c1): mysql> EXPLAIN SELECT * FROM t1 WHERE c1=1 AND (c2,c3) > (1,1)\G *************************** 1. The ...
https://dev.mysql.com/doc/refman/8.4/en/replication-features-row-searches.html
When a replica using row-based replication format applies an UPDATE or DELETE operation, it must search the relevant table for the matching rows. Any index where the before-image of the row event does not contain all the columns of the index. If ...
https://dev.mysql.com/doc/mysql-em-plugin/en/myoem-performance-page-tables-rows.html
The Global Table/Row Statistics dashboard displays information on the table and row activity on the monitored server. Table 5.9 Tables / Rows Performance Page Regions NameDescriptionOpened Tables Graphs the number of cached frm files and the total ...Currently Open Tables Graphs the number of tables open in the table ...
https://dev.mysql.com/doc/internals/en/join-buffer-size.html
If join_buffer_size is already large enough to hold all previous row combinations, there is no speed to be gained by making it larger. Basic information about the join buffer cache: The size of each join buffer is determined by the value of the ...
https://dev.mysql.com/doc/refman/8.4/en/no-matching-rows.html
If you have a complicated query that uses many tables but that returns no rows, you should use the following procedure to find out what is wrong: Test the query with EXPLAIN to check whether you can find something that is obviously wrong. Remove ...
https://dev.mysql.com/doc/refman/8.4/en/selecting-rows.html
But typically you don't want to see the entire table, particularly when it becomes large. As shown in the preceding section, it is easy to retrieve an entire table. Instead, you're usually more interested in answering a particular question, in ...
https://dev.mysql.com/doc/refman/8.4/en/counting-rows.html
Counting the total number of animals you have is the same question as “How many rows are in the pet table?” because there is one record per pet. COUNT(*) counts the number of rows, so the query to count your animals looks like this: mysql> ...
https://dev.mysql.com/doc/internals/en/binary-protocol-resultset-row.html
A Binary Protocol Resultset Row is made up of the NULL bitmap containing as many bits as we have columns in the resultset + 2 and the values for columns that are not NULL in the Binary Protocol Value format. ProtocolBinary::ResultsetRow: row of a ...
https://dev.mysql.com/doc/internals/en/row-order-within-result-sets.html
Please keep in mind that the row order within a significant number of result sets depends on storage engine properties and in worst cases the current load (NDB!, partitioning?, parallel query?) on the testing box. Either use --sorted_result SELECT ...