PDF (US Ltr)
- 35.1Mb
PDF (A4)
- 35.2Mb
Man Pages (TGZ)
- 256.4Kb
Man Pages (Zip)
- 361.2Kb
Info (Gzip)
- 3.4Mb
Info (Zip)
- 3.4Mb
Search Results
https://dev.mysql.com/doc/refman/5.7/en/group-by-handling.html
SQL-92 and earlier does not permit queries for which the select list, HAVING condition, or ORDER BY list refer to nonaggregated columns that are not named in the GROUP BY clause. If the ONLY_FULL_GROUP_BY SQL mode is enabled (which it is by ...
https://dev.mysql.com/doc/refman/5.7/en/added-deprecated-removed.html
Qcache_lowmem_prunes: Number of queries which were deleted from query cache due to lack of free memory in cache. Qcache_not_cached: Number of noncached queries (not cacheable, or not cached due to query_cache_type setting). Options and Variables ...
https://dev.mysql.com/doc/refman/5.7/en/select-optimization.html
Queries, in the form of SELECT statements, perform all the lookup operations in the database. Besides SELECT statements, the tuning techniques for queries also apply to constructs such as CREATE TABLE...AS SELECT, INSERT INTO...SELECT, and WHERE ...
https://dev.mysql.com/doc/refman/5.7/en/outer-join-simplification.html
At the parser stage, queries with right outer join operations are converted to equivalent queries containing only left join operations. Table expressions in the FROM clause of a query are simplified in many cases. When the optimizer evaluates plans ...
https://dev.mysql.com/doc/refman/5.7/en/sql-mode.html
ONLY_FULL_GROUP_BY Reject queries for which the select list, HAVING condition, or ORDER BY list refer to nonaggregated columns that are neither named in the GROUP BY clause nor are functionally dependent on (uniquely determined by) GROUP BY columns.
https://dev.mysql.com/doc/refman/5.7/en/group-by-optimization.html
If the WHERE clause contains range predicates (see the discussion of the range join type in Section 8.8.1, “Optimizing Queries with EXPLAIN”), a Loose Index Scan looks up the first key of each group that satisfies the range conditions, and again ... The most general way to satisfy a GROUP BY clause is to scan the whole table and create a new temporary table where all rows from each group are consecutive, and then use this temporary table to discover groups and apply aggregate functions (if ...
https://dev.mysql.com/doc/refman/5.7/en/innodb-information-schema-buffer-pool-tables.html
The InnoDB INFORMATION_SCHEMA buffer pool tables provide buffer pool status information and metadata about the pages within the InnoDB buffer pool. The InnoDB INFORMATION_SCHEMA buffer pool tables include those listed below: mysql> SHOW TABLES FROM ...
https://dev.mysql.com/doc/refman/5.7/en/show-profile.html
For example, the following queries are equivalent: SHOW PROFILE FOR QUERY 2; SELECT STATE, FORMAT(DURATION, 6) AS DURATION FROM INFORMATION_SCHEMA.PROFILING WHERE QUERY_ID = 2 ORDER BY SEQ; . Note The SHOW PROFILE and SHOW PROFILES statements are ...
https://dev.mysql.com/doc/refman/5.7/en/group-replication-adding-instances.html
At this point, the group has one member in it, server s1, which has some data in it. It is now time to expand the group by adding the other two servers configured previously. 17.2.1.6.1 Adding a Second Instance In order to add a second instance, ...
https://dev.mysql.com/doc/refman/5.7/en/mysql-cluster-programs-ndb-config.html
To exclude results from any host except one in particular, use the --host option: $> ./ndb_config --host=198.51.100.176 -f : -r '\n' -q id,type 3:ndbd 5:ndb_mgmd In this example, we also used the short form -q to determine the attributes to be ...